Clinical implications of the 'no reflow' phenomenon. A predictor of complications and left ventricular remodeling in reperfused anterior wall myocardial infarction

Intracoronary adenosine compared with adrenaline and verapamil in the treatment of no-reflow phenomenon following primary PCI in STEMI patients

BACKGROUND

no-reflow can complicate up to 25% of pPCI and is associated with significant morbidity and mortality. We aimed to compare the outcomes of intracoronary epinephrine and verapamil with intracoronary adenosine in the treatment of no-reflow after primary percutaneous coronary intervention (pPCI).

METHODS

108 STEMI patients had no-reflow during pPCI were assigned into four groups. Group 1, in which epinephrine and verapamil were injected through a well-cannulated guiding catheter. Group 2, in which same drugs were injected in the distal coronary bed through a microcatheter or perfusion catheter. Group 3, in which adenosine was injected through a guiding catheter. Group 4, in which adenosine was injected in distal coronary bed. Primary end point was the achievement of TIMI III flow and MBG II or III. Secondary end point was major adverse cardiovascular and cerebrovascular events (MACCEs) during hospital stay.

RESULTS

The study groups did not differ in their baseline characteristics. Primary end point was achieved in 15 (27.8%) patients in the guide-delivery arm compared with 34 (63%) patients in the local-delivery arm, p < 0.01. However, the primary end point did not differ between the epinephrine/verapamil group and the adenosine group (27 (50%) vs 22 (40.7%), p = 0.334). The secondary end points were similar between the study groups.

CONCLUSION

Local delivery of epinephrine, verapamil and adenosine in the distal coronary bed is more effective in achieving TIMI III flow with MBG II or III compared with their guide-delivery in patients who suffered no-reflow during pPCI. There was no difference between epinephrine/verapamil Vs. adenosine.

Coronary no-reflow and adverse events in patients with acute myocardial infarction after percutaneous coronary intervention with current drug-eluting stents and third-generation P2Y12 inhibitors

BACKGROUND

The frequency and prognostic value of coronary no-reflow (CNR) was investigated in studies that have used an outdated reperfusion therapy in terms of stent technology and antithrombotic drugs. We assessed the association of CNR with adverse outcomes in patients with acute myocardial infarction (AMI) undergoing percutaneous coronary intervention (PCI) with drug-eluting stents (DES) and newer antithrombotic drugs, ticagrelor or prasugrel.

METHODS

This study included 3100 patients with AMI who underwent PCI with current DES and third-generation P2Y12 inhibitors. CNR was defined as Thrombolysis in Myocardial Infarction (TIMI) blood flow grade ≤ 2 at the end of PCI. The primary end point was 1-year incidence of net adverse clinical and cerebral events-a composite end point of death of any cause, myocardial infarction, stroke or major bleeding.

RESULTS

CNR was diagnosed in 130 patients (4.2%). The primary end point occurred in 28 patients in the CNR group and 354 patients in the reflow group (cumulative incidence 23.2% and 12.8%; adjusted hazard ratio = 1.53, 95% confidence interval 1.01-2.33; P = 0.049). The 1-year incidences of death or myocardial infarction (14.6% vs. 7.6%; P = 0.003), myocardial infarction (8.8% vs. 3.9%; P = 0.007) and major bleeding (10.9% vs. 5.6%; P = 0.008) were significantly higher in patients with CNR than patients with reflow. The risk of adverse events in patients with CNR was highest within the first 30 days after PCI.

CONCLUSION

In patients with AMI undergoing PCI with current DES and third generation P2Y12 receptor inhibitors, CNR was associated with a higher risk of adverse outcomes at 1 year.

Microvascular recovery with ultrasound in myocardial infarction post-PCI trial

PURPOSE

Persistent microvascular obstruction (MVO) after successful percutaneous coronary intervention (PCI) in acute ST segment elevation myocardial infarction (STEMI) has been well-described. MVO predicts lack of recovery of left ventricular function and increased mortality. Sonothrombolysis utilizing diagnostic ultrasound induced cavitation of commercially available microbubble contrast has been effective at reducing infarct size and improving left ventricular ejection fraction (LVEF) when performed both pre- and post-PCI. However, the effectiveness of post-PCI sonothrombolysis alone after successful PCI has not been demonstrated.

METHODS

A prospective randomized controlled trial was performed in 50 consecutive consenting patients with anterior STEMI who underwent a continuous microbubble infusion immediately following successful PCI. Intermittent high mechanical index (MI) impulses were applied only in the sonthrombolysis group. Delayed enhancement magnetic resonance imaging (MRI) was performed at 48 h and again at 6-8 weeks to assess for differences in infarct size, LVEF, and MVO.

RESULTS

There were no differences between groups in age, gender, and cardiovascular risk factors. Significant (> 2 segments) MVO following successful PCI was observed in 66% of patients. Although sonothrombolysis reduced the extent of MVO acutely, there were no differences in infarct size, LVEF, or extent of MVO by MRI at 48 h. Twenty-eight patients returned for a follow up MRI at 6-8 weeks. LVEF improved only in the sonothrombolysis group (∆LVEF 7.81 ± 4.57% with sonothrombolysis vs. 1.77 ± 7.02% for low MI only, p = .011).

CONCLUSION

Post-PCI sonothrombolysis had minimal effect on reducing myocardial infarct size but improved left ventricular systolic function in patients with acute anterior wall STEMI.

Association of Pre-PCI Blood Pressure and No-Reflow in Patients with Acute ST-Elevation Coronary Infarction

Background

Previous studies have established blood pressure (BP) as a pivotal factor influencing no-reflow following primary percutaneous coronary intervention (PCI) in patients with ST-elevation acute coronary infarction (STEMI). However, no relevant study has been conducted to investigate the optimal range of BP associated with the lowest risk of no-reflow among STEMI patients so far. Therefore, our objective was to evaluate the association between pre-PCI BP and the occurrence of no-reflow in patients with STEMI.

Method

We included 1025 STEMI patients undergoing primary PCI. The BP pre-PCI was categorized into 20-mmHg increments. Logistic models were employed to assess the association of no-reflow with systolic blood pressure (SBP) or diastolic blood pressure (DBP). Three sensitivity analyses were conducted to further confirm the robustness of the association between blood pressure and no-reflow.

Results

SBP or DBP exhibited a U-shaped curve association with no-reflow. No-reflow was higher in patients with lower SBP (<100 mmHg) (adjusted hazard ratio (OR) 3.64, 95% confidence interval (CI) 1.84,7.21; p < 0.001) and lower DBP (<60 mmHg) (OR 3.28, 95% CI 1.63,6.49; p < 0.001) [reference: 120 ≤SBP <140; 80 ≤DBP <100 mmHg], respectively. Furthermore, no-reflow was higher in patients with higher SBP (≥160 mmHg) (OR 2.07, 95% CI 1.27,3.36; p = 0.003) and DBP (≥100 mmHg) (OR 3.36, 95% CI 2.07,5.46; p < 0.001), respectively. The results of sensitivity analyses were consistent with the above findings.

Conclusion

Maintaining a pre-PCI SBP within the range of 120 to 140 mmHg and a DBP within the range of 80 to 100 mmHg may be confer benefits to patients with STEMI in no-reflow.

Utility of electrocardiogram to predict the occurrence of the no-reflow phenomenon in patients undergoing primary percutaneous coronary intervention (PPCI): a systematic review and meta-analysis

Background

The no-reflow phenomenon affects about one out of five patients undergoing Primary Percutaneous Coronary Intervention (PPCI). As the prolonged no-reflow phenomenon is linked with unfavorable outcomes, making early recognition is crucial for effective management and improved clinical outcomes in these patients. Our review study aimed to determine whether electrocardiogram (ECG) findings before PCI could serve as predictors for the occurrence of the no-reflow phenomenon.

Methods and materials

We systematically searched MEDLINE, Scopus, and Embase to identify relevant studies. The random-effect model using inverse variance and Mantel-Haenszel methods were used to pool the standardized mean differences (SMD) and odds ratios (OR), respectively.

Result

Sixteen eligible articles (1,473 cases and 4,264 controls) were included in this study. Based on our meta-analysis of baseline ECG findings, the no-reflow group compared to the control group significantly had a higher frequency of fragmented QRS complexes (fQRS) (OR (95% CI): 1.35 (0.32-2.38), P-value = 0.01), and Q-waves (OR (95% CI): 1.97 (1.01-2.94), P-value <0.001). Also, a longer QRS duration (QRSD) (SMD (95% CI): 0.72 (0.21, 1.23), p-value <0.001) and R wave peak time (RWPT) (SMD (95% CI): 1.36 (0.8, 1.93), P < 0.001) were seen in the no-reflow group. The two groups had no significant difference regarding P wave peak time (PWPT), and P wave maximum duration (Pmax) on baseline ECG.

Conclusion

Our findings suggest that prolonged QRSD, delayed RWPT, higher fQRS prevalence, and the presence of a Q wave on baseline ECG may predict the occurrence of the no-reflow phenomenon in patients undergoing PPCI.

Angiographic Predictors of Viability During Intervention for a ST Elevation Myocardial Infarction

Objectives

This study aimed to identify angiographic features that would predict myocardial viability after coronary intervention for ST elevation myocardial infarction (STEMI).

Methods

This retrospective study included patients who attended Sultan Qaboos University Hospital, Muscat, Oman, between January and December 2019 with a STEMI.

Results

A total of 72 patients (61 male; mean age = 54.9 ± 12.7 years) were included in the study; 11 patients had evidence of non-viability on echocardiography. There were 13 patients with viable myocardium and 3 with non-viable myocardium who had a myocardial blush grade (MBG) of 2 or lower. Similarly, 10 patients with viability and 1 with non-viable myocardium had thrombolysis in myocardial infarction (TIMI) flow of 2 or lower in the infarct related artery (IRA). However, none of these were statistically significant. The TIMI flow in the IRA at the end of the procedure correlated with the MBG.

Conclusion

There were no clear angiographic features during primary angioplasty that could predict myocardial viability.

Heart graft preservation technics and limits: an update and perspectives

Heart transplantation, the gold standard treatment for end-stage heart failure, is limited by heart graft shortage, justifying expansion of the donor pool. Currently, static cold storage (SCS) of hearts from donations after brainstem death remains the standard practice, but it is usually limited to 240 min. Prolonged cold ischemia and ischemia-reperfusion injury (IRI) have been recognized as major causes of post-transplant graft failure. Continuous ex situ perfusion is a new approach for donor organ management to expand the donor pool and/or increase the utilization rate. Continuous ex situ machine perfusion (MP) can satisfy the metabolic needs of the myocardium, minimizing irreversible ischemic cell damage and cell death. Several hypothermic or normothermic MP methods have been developed and studied, particularly in the preclinical setting, but whether MP is superior to SCS remains controversial. Other approaches seem to be interesting for extending the pool of heart graft donors, such as blocking the paths of apoptosis and necrosis, extracellular vesicle therapy, or donor heart-specific gene therapy. In this systematic review, we summarize the mechanisms involved in IRI during heart transplantation and existing targeting therapies. We also critically evaluate all available data on continuous ex situ perfusion devices for adult donor hearts, highlighting its therapeutic potential and current limitations and shortcomings.

Mesenchymal Stem Cell-Originated Exosomal Lnc A2M-AS1 Alleviates Hypoxia/Reperfusion-Induced Apoptosis and Oxidative Stress in Cardiomyocytes

BACKGROUND

Mesenchymal stem cell (MSC)-derived exosomes play significant roles in ameliorating cardiac damage after myocardial ischemia-reperfusion (I/R) injury. Long non-coding RNA alpha-2-macroglobulin antisense RNA 1 (Lnc A2M-AS1) was found that might protect against myocardial I/R. However, whether Lnc A2M-AS1 delivery via MSC-derived exosomes could also regulate myocardial I/R injury remains unknown.

METHODS

Exosomes were isolated by ultracentrifugation, and qualified by transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), and Western blot. Hypoxia/reoxygenation (H/R) treatment in human cardiomyocytes was used to mimic the process of myocardial I/R in vitro. The viability and apoptosis of cardiomyocytes were detected using cell counting kit-8, flow cytometry, and Western blot assays. The contents of lactate dehydrogenase (LDH), malondialdehyde (MDA), and superoxide dismutase (SOD) were evaluated using corresponding commercial kits. The quantitative real-time polymerase chain reaction and Western blot were used to determine the expression levels of Lnc A2M-AS1, microRNA (miR)-556-5p, and X-linked inhibitor of apoptosis protein (XIAP). The binding interaction between miR-556-5p and Lnc A2M-AS1 or XIAP was confirmed by the dual-luciferase reporter, RIP and pull-down assays.

RESULTS

Exosomes isolated from hMSCs (hMSCs-exo) attenuated H/R-induced apoptosis and oxidative stress in cardiomyocytes. Lnc A2M-AS1 was lowly expressed in AMI patients and H/R-induced cardiomyocytes. Besides, Lnc A2M-AS1 was detectable in hMSCs-exo, exosomes derived from Lnc A2M-AS1-transfected hMSCs weakened H/R-induced apoptosis and oxidative stress, and enhanced the protective action of hMSCs-exo on H/R-induced cardiomyocytes. Further mechanism analysis showed that Lnc A2M-AS1 acted as a sponge for miR-556-5p to increase XIAP expression level. Importantly, miR-556-5p overexpression or XIAP knockdown reversed the action of exosomal Lnc A2M-AS1 on H/R-induced cardiomyocytes.

CONCLUSION

Lnc A2M-AS1 delivery via MSC-derived exosomes ameliorated H/R-induced cardiomyocyte apoptosis and oxidative stress via regulating miR-556-5p/XIAP, opening a new window into the pathogenesis of myocardial I/R injury.

Predictors of diastolic deceleration time of coronary flow velocity of infarct related and reference coronary artery assessed by transthoracic Doppler echocardiography in the chronic phase of successfully reperfused anterior myocardial infarction: relation to infarct size

Introduction

High-frequency transthoracic Doppler echocardiography (TDE) enables the assessment of flow velocity and velocity pattern in different coronary arteries, including the assessment of diastolic deceleration time (DDT) of coronary flow velocity. Short DDT of infarct related artery (IRA) (<600 msec) in the acute phase of anterior myocardial infarction (MI) is the predictor of adverse left ventricular (LV) remodeling and prognosis. The significance of DDT of coronary flow velocity assessment in the chronic phase of anterior MI is not well established. Our study aimed to establish the predictors of DDT of the coronary flow velocity of infarct related (left anterior descendent-DDT of LAD) and reference coronary artery, evaluated by TDE, and to assess their relation to infarct size in the chronic phase of successfully reperfused first anterior MI.

Methods

Our study included 40 consecutive patients (34 men, mean age 52 ± 12 years) one month after the first anterior STEMI and single vessel disease successfully treated with primary PCI. All patients underwent SPECT MPI for the assessment of LV volumes, ejection fraction, and percentage of the myocardium with fixed perfusion abnormalities and echocardiographic examination including the evaluation of DDT of IRA and reference coronary artery TDE.

Results

DDT of LAD correlated significantly to the WMSI (r = -0.467, p = 0.002), LV end-systolic volume (r = -0.412, p = 0.008), LV ejection fraction (r = 0.427, p = 0.006), while the strongest correlation was observed between DDT of LAD and the extent of fixed perfusion abnormality (r = -0.627, p < 0.0001), Multivariate analysis revealed percentage of fixed perfusion abnormalities along with DDT of reference coronary artery as the independent predictors of DDT of IRA. DDT of IRA shorter than 886 msec predicts large fixed perfusion abnormalities (>20%) with a sensitivity of 89% and specificity of 62% (AUC 0.842).

Conclusion

DDT of LAD assessed by TDE in the chronic phase of successfully reperfused first anterior MI is a usefull variable for the assessment of microcirculatory function that exclusively reflects the extent of microvascular damage and relates to infarct size.

Coronary No-Reflow after Primary Percutaneous Coronary Intervention-Current Knowledge on Pathophysiology, Diagnosis, Clinical Impact and Therapy

Coronary no-reflow (CNR) is a frequent phenomenon that develops in patients with ST-segment elevation myocardial infarction (STEMI) following reperfusion therapy. CNR is highly dynamic, develops gradually (over hours) and persists for days to weeks after reperfusion. Microvascular obstruction (MVO) developing as a consequence of myocardial ischemia, distal embolization and reperfusion-related injury is the main pathophysiological mechanism of CNR. The frequency of CNR or MVO after primary PCI differs widely depending on the sensitivity of the tools used for diagnosis and timing of examination. Coronary angiography is readily available and most convenient to diagnose CNR but it is highly conservative and underestimates the true frequency of CNR. Cardiac magnetic resonance (CMR) imaging is the most sensitive method to diagnose MVO and CNR that provides information on the presence, localization and extent of MVO. CMR imaging detects intramyocardial hemorrhage and accurately estimates the infarct size. MVO and CNR markedly negate the benefits of reperfusion therapy and contribute to poor clinical outcomes including adverse remodeling of left ventricle, worsening or new congestive heart failure and reduced survival. Despite extensive research and the use of therapies that target almost all known pathophysiological mechanisms of CNR, no therapy has been found that prevents or reverses CNR and provides consistent clinical benefit in patients with STEMI undergoing reperfusion. Currently, the prevention or alleviation of MVO and CNR remain unmet goals in the therapy of STEMI that continue to be under intense research.

Dynamic Behavior of Polymer Microbubbles During Long Ultrasound Tone-Burst Excitation and Its Application for Sonoreperfusion Therapy

OBJECTIVE

Ultrasound (US)-targeted microbubble (MB) cavitation (UTMC)-mediated therapies have been found to restore perfusion and enhance drug/gene delivery. Because of the potentially longer circulation time and relative ease of storage and reconstitution of polymer-shelled MBs compared with lipid MBs, we investigated the dynamic behavior of polymer microbubbles and their therapeutic potential for sonoreperfusion (SRP) therapy.

METHODS

The fate of polymer MBs during a single long tone-burst exposure (1 MHz, 5 ms) at various acoustic pressures and MB concentrations was recorded via high-speed microscopy and passive cavitation detection (PCD). SRP efficacy of the polymer MBs was investigated in an in vitro flow system and compared with that of lipid MBs.

DISCUSSION

Microscopy videos indicated that polymer MBs formed gas-filled clusters that continued to oscillate, fragment and form new gas-filled clusters during the single US burst. PCD confirmed continued acoustic activity throughout the 5-ms US excitation. SRP efficacy with polymer MBs increased with pulse duration and acoustic pressure similarly to that with lipid MBs but no significant differences were found between polymer and lipid MBs.

CONCLUSION

These data suggest that persistent cavitation activity from polymer MBs during long tone-burst US excitation confers excellent reperfusion efficacy.

Sustained Mechanical Aspiration Thrombectomy for High Thrombus Burden Coronary Vessel Occlusion: The Multicenter CHEETAH Study

BACKGROUND

Poor myocardial reperfusion due to distal embolization and microvascular obstruction after percutaneous coronary intervention is associated with increased risk of morbidity and mortality. Prior trials have not shown a clear benefit of routine manual aspiration thrombectomy. Sustained mechanical aspiration may mitigate this risk and improve outcomes. The objective of this study is to evaluate sustained mechanical aspiration thrombectomy before percutaneous coronary intervention in high thrombus burden acute coronary syndrome patients.

METHODS

This prospective study evaluated the Indigo CAT RX Aspiration System (Penumbra Inc, Alameda CA) for sustained mechanical aspiration thrombectomy before percutaneous coronary intervention at 25 hospitals across the USA. Adults presenting within 12 hours of symptom onset with high thrombus burden and target lesion(s) located in a native coronary artery were eligible. The primary end point was a composite of cardiovascular death, recurrent myocardial infarction, cardiogenic shock, or new or worsening New York Heart Association class IV heart failure within 30 days. Secondary end points included Thrombolysis in Myocardial Infarction thrombus grade, Thrombolysis in Myocardial Infarction flow, myocardial blush grade, stroke, and device-related serious adverse events.

RESULTS

From August 2019 through December 2020, a total of 400 patients were enrolled (mean age 60.4 years, 76.25% male). The primary composite end point rate was 3.60% (14/389 [95% CI, 2.0-6.0%]). Rate of stroke within 30 days was 0.77%. Final rates of Thrombolysis in Myocardial Infarction thrombus grade 0, Thrombolysis in Myocardial Infarction flow 3, and myocardial blush grade 3 were 99.50%, 97.50%, and 99.75%, respectively. No device-related serious adverse events occurred.

CONCLUSIONS

Sustained mechanical aspiration before percutaneous coronary intervention in high thrombus burden acute coronary syndrome patients was safe and was associated with high rates of thrombus removal, flow restoration, and normal myocardial perfusion on final angiography.

Low Quantitative Blush Evaluator score predicts larger infarct size and reduced left ventricular systolic function in patients with STEMI regardless of diabetes status

Type 2 diabetes mellitus (T2DM) and diminished myocardial perfusion increase the risk of heart failure (HF) and/or all-cause mortality during 6-year follow up following primary percutaneous coronary intervention (pPCI) for ST elevation myocardial infarction (STEMI). The aim of the present study was to evaluate the impact of myocardial perfusion on infarct size and left ventricular ejection fraction (LVEF) in patients with T2DM and STEMI treated with pPCI. This is an ancillary analysis of an observational cohort study of T2DM patients with STEMI. We enrolled 406 patients with STEMI, including 104 with T2DM. Myocardial perfusion was assessed with the Quantitative Myocardial Blush Evaluator (QUBE) and infarct size with the creatine kinase myocardial band (CK-MB) maximal activity and troponin area under the curve. LVEF was measured with biplane echocardiography using Simpson's method at admission and hospital discharge. Analysis of covariance was used for modeling the association between myocardial perfusion, infarct size and left ventricular systolic function. Patients with T2DM and diminished perfusion (QUBE below median) had the highest CK-MB maximal activity (252.7 ± 307.2 IU/L, P < 0.01) along with the lowest LVEF (40.6 ± 10.0, P < 0.001). Older age (p = 0.001), QuBE below median (p = 0.026), and maximal CK-MB activity (p < 0.001) were independent predictors of LVEF. Diminished myocardial perfusion assessed by QuBE predicts significantly larger enzymatic infarct size and lower LVEF among patients with STEMI treated with pPCI, regardless of diabetes status.

Evaluation of Coronary Flow Level with Mots-C in Patients with STEMI Undergoing Primary PCI

BACKGROUND

The protective effects of mitochondrial open reading frame of the 12S rRNA-c (MOTS-C) on cardiovascular diseases have been shown in numerous studies. However, there is little documentation of the relationship between MOTS-C and coronary blood flow in ST-segment elevation myocardial infarction (STEMI).

OBJECTIVE

We aimed to investigate the role of MOTS-C, which is known to have cytoprotective properties in the pathogenesis of the no-reflow phenomenon, by comparing the coronary flow rate and MOTS-C levels in patients with STEMI submitted to primary PCI.

METHODS

52 patients with STEMI and 42 patients without stenosis >50% in the coronary arteries were included in the study. The STEMI group was divided into two groups according to post-PCI TIMI (Thrombolysis In Myocardial Infarction) flow grade:(i) No-reflow: grade 0, 1, and 2 and (ii) grade 3(angiographic success). A p value of <0.05 was considered significant.

RESULTS

MOTS-C levels were significantly lower in the STEMI group compared to the control group (91.9 ± 8.9 pg/mL vs. 171.8±12.5 pg/mL, p<0.001). In addition, the Receiver Operating Characteristics (ROC) curve analysis indicated that serum MOTS-C levels had a diagnostic value in predicting no-reflow (Area Under the ROC curve [AUC]:0.95, 95% CI:0.856-0.993, p<0.001). A MOTS-C ≥84.15 pg/mL measured at admission was shown to have 95.3% sensitivity and 88.9% specificity in predicting no-reflow.

CONCLUSION

MOTS-C is a strong and independent predictor of no-reflow and in-hospital MACE in patients with STEMI. It was also noted that low MOTS-C levels may be an important prognostic marker of and may have a role in the pathogenesis of STEMI.

Multimodality Imaging of Sudden Cardiac Death and Acute Complications in Acute Coronary Syndrome

Sudden cardiac death (SCD) is a potentially fatal event usually caused by a cardiac arrhythmia, which is often the result of coronary artery disease (CAD). Up to 80% of patients suffering from SCD have concomitant CAD. Arrhythmic complications may occur in patients with acute coronary syndrome (ACS) before admission, during revascularization procedures, and in hospital intensive care monitoring. In addition, about 20% of patients who survive cardiac arrest develop a transmural myocardial infarction (MI). Prevention of ACS can be evaluated in selected patients using cardiac computed tomography angiography (CCTA), while diagnosis can be depicted using electrocardiography (ECG), and complications can be evaluated with cardiac magnetic resonance (CMR) and echocardiography. CCTA can evaluate plaque, burden of disease, stenosis, and adverse plaque characteristics, in patients with chest pain. ECG and echocardiography are the first-line tests for ACS and are affordable and useful for diagnosis. CMR can evaluate function and the presence of complications after ACS, such as development of ventricular thrombus and presence of myocardial tissue characterization abnormalities that can be the substrate of ventricular arrhythmias.

Soluble ST2 in coronary artery disease: Clinical biomarkers and treatment guidance

The IL-33/ST2 L signaling pathway is involved in the pathophysiological processes of several diseases and mainly exerts anti-inflammatory and antifibrotic effects. Soluble suppression of tumorigenicity 2 (sST2), which serves as a competitive inhibitory molecule of this pathway, is a member of the interleukin (IL)-1 family, a decoy receptor for IL33, thought to play a role in cardiac remodeling and the inflammatory process. However, the association between sST2 and coronary artery disease (CAD), one of the most common causes of heart failure, is still being explored. We therefore reviewed the research on sST2 in the field of CAD, including reflecting the atherosclerosis burden, predicting no-reflow, predicting prognosis, responding to myocardial remodeling, and guiding management, hoping to provide cardiologists with new perspectives.

Use of a Cutting Balloon Reduces the Incidence of Distal Embolism in Acute Coronary Syndrome Requiring Predilatation Before Stenting

Background: Acute coronary syndrome (ACS) patients with solid lesions often require predilatation before stenting. Predilatation with high pressure may increase the risk of distal embolism, whereas direct stenting increases the risk of stent underexpansion. We recently reported that, in severely calcified lesions, using a cutting balloon (CB) can provide greater acute gain compared with other scoring balloons. Therefore, we hypothesized that predilatation with CB may reduce the incidence of distal embolism in ACS patients with solid lesions.

Methods and Results: This study retrospectively analyzed data for 175 ACS patients who required predilatation, either with a conventional balloon (n=136) or CB (n=39). The occurrence of distal embolism was significantly lower in the CB than conventional balloon group (10.3% vs 32.4%, respectively; P=0.007). Multivariate analysis showed that the occurrence of distal embolism was positively associated with Thrombolysis in Myocardial Infarction (TIMI) grade and the presence of attenuated plaque, but negatively associated with the use of a CB. To support this clinical observation, we compared thrombus dispersal using a CB and non-compliant balloon in an ex vivo experimental model using a pseudo-thrombus. In this model, pseudo-thrombus dispersal was significantly smaller when a CB rather than non-compliant balloon was used (1.8±1.0% vs 2.6±1.2%, respectively; n=20, for each; P=0.002).

Conclusions: In ACS patients with solid lesions that require predilatation, predilatation with a CB may reduce the incidence of distal embolism.

Prognostic significance of thrombus burden on short- and long-term clinical outcomes in patients with ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention

OBJECTIVE

Large thrombus burden (LTB) observed during ST-segment elevation myocardial infarction (STEMI) may end up with worse clinical outcomes. The relationship between LTB and long-term mortality and major adverse cardiac events (MACE) in STEMI patients undergoing percutaneous coronary intervention (PCI) is unclear. In this study, we aimed to investigate the relationship of LTB with short- and long-term mortality and MACE in STEMI patients undergoing PCI.

METHODS

Thrombus burden (TB) was evaluated in STEMI patients who underwent PCI between December 2010 and April 2012. After infarct-related arterial flow was restored, TB was reclassified. LTB was defined as thrombus with the largest dimension of at least two vessel diameters. Patients were evaluated for 1-month, 1-year, and 10-year follow-ups in terms of MACE and mortality.

RESULTS

Four hundred ninety-nine patients with clinical information and TB classification were analyzed. Three hundred sixty-six patients (73.3%) were in the small TB (STB) group, and 133 patients (26.7%) were in the LTB group. No-reflow (10.6% vs. 5.2%; P = 0.033) and stent thrombosis (7.5% vs. 3.3%; P = 0.042) were observed at a higher rate in the LTB group compared with the STB group. Thirty-day mortality (9.8% vs. 3.8%; P = 0.009) and MACE (16.5% vs. 9.6%; P = 0.030) were higher in the LTB group than in the STB group. Although 10-year MACE (56.4% vs. 46.2%; P = 0.044) was observed higher in the LTB group, no significant difference was observed between the two groups in terms of 10-year mortality (35.3% vs. 32.8%; P = 0.589). LTB was found to be an independent predictor for 10-year MACE (OR, 1.62; 95% CI, 1.01-2.61; P = 0.045).

CONCLUSION

LTB was associated with short- and long-term clinical events in STEMI patients undergoing PCI, but the mortality effect disappeared at the end of 1 year. Nevertheless, hospitalizations due to heart failure became significant in 10-year follow-up.

Assessment and Treatment for Coronary Microvascular Dysfunction by Contrast Enhanced Ultrasound

With growing evidence in clinical practice, the understanding of coronary syndromes has gradually evolved out of focusing on the well-established link between stenosis of epicardial coronary artery and myocardial ischemia to the structural and functional abnormalities at the level of coronary microcirculation, known as coronary microvascular dysfunction (CMD). CMD encompasses several pathophysiological mechanisms of coronary microcirculation and is considered as an important cause of myocardial ischemia in patients with angina symptoms without obstructive coronary artery disease (CAD). As a result of growing knowledge of the understanding of CMD assessed by multiple non-invasive modalities, CMD has also been found to be involved in other cardiovascular diseases, including primary cardiomyopathies as well as heart failure with preserved ejection fraction (HFpEF). In the past 2 decades, almost all the imaging modalities have been used to non-invasively quantify myocardial blood flow (MBF) and promote a better understanding of CMD. Myocardial contrast echocardiography (MCE) is a breakthrough as a non-invasive technique, which enables assessment of myocardial perfusion and quantification of MBF, exhibiting promising diagnostic performances that were comparable to other non-invasive techniques. With unique advantages over other non-invasive techniques, MCE has gradually developed into a novel modality for assessment of the coronary microvasculature, which may provide novel insights into the pathophysiological role of CMD in different clinical conditions. Moreover, the sonothrombolysis and the application of artificial intelligence (AI) will offer the opportunity to extend the use of contrast ultrasound theragnostics.

Combined therapy with dapagliflozin and entresto offers an additional benefit on improving the heart function in rat after ischemia-reperfusion injury

BACKGROUND

This study tested whether combined dapagliflozin and entresto treatment would be superior to either one alone for preserving the left-ventricular ejection-fraction (LVEF) in rat after ischemia-reperfusion (IR) injury.

METHODS AND RESULTS

In vitro flow-cytometric result showed that the intracellular and mitochondrial reactive oxygen species and mitochondrial permeability transition pore, and protein levels of oxidative-stress/DNA-damaged markers [NADPH-oxidase-1 (NOX-1)/NOX-2/oxidized-protein/γ-H2A-histone-family member X (γ-H2AX)] were significantly higher in hydrogen peroxide (H₂O₂) (300μM)-treated H9C2 cells as compared with the controls that were significantly reversed in sacubitril/valsartan and dapagliflozin therapy in the same H₂O₂-treated condition, whereas the protein expressions of antioxidants [Sirtuin-1 (SIRT1)/SIRT3/superoxide dismutase/catalase/glutathione peroxidase) exhibited an opposite pattern among the groups (all p<0.001). Adult-male-Sprague-Dawley rat (n=40) were equally categorized into group 1 (sham-operated control), group 2 (IR), group 3 (IR+dapagliflozin/20mg/kg/orally at 3h and post-days 1/2/3 after IR), group 4 (IR+entresto/100mg/kg/orally at 3h and post-days 1/2/3 after IR) and group 5 (IR+dapagliflozin+entresto) and the hearts were harvested by day 3 after IR. The 3^rd day's LVEF was highest in group 1, lowest in group 2 and significantly higher in group 5 than in groups 3/4, but it was similar between the latter two groups (p<0.001). The protein expressions of oxidative-stress (NOX-1/NOX-2/oxidized protein), fibrotic (transforming-growth factor-ß/phosphorylated-Smad3), apoptotic [mitochondrial-Bax/cleaved-caspase-3/cleaved-poly (ADP-ribose) polymerase], mitochondria/DNA damaged (cytosolic-cytochrome-C/γ-H2AX), pressure-overload/heart-failure [brain natriuretic peptide (BNP)/ß-myosin heavy chain] and autophagic (ratio of meiotic cyclins CLB3-II/CLB3-I) biomarkers, and the upstream (high-mobility group box 1/Toll-like receptor-4/MyD88/phosphorylated-nuclear factor-κB and downstream [interleukin (IL)-1ß/IL-6/tumor necrosis factor-α] inflammatory signalings revealed an antithetical features of LVEF among the groups (all p<0.0001). The cellular levels of inflammatory (myeloperoxidase+/CD68+), pressure-overload/heart-failure (BNP+) and DNA-damage (γ-H2AX+) biomarkers as well as infarct area demonstrated an opposite pattern of LVEF among the groups (all p<0.0001).

CONCLUSION

Incorporated entresto-dapagliflozin treatment was superior to either one alone on protecting the heart against IR injury.

Efficacy of Shexiang Tongxin Dropping Pills in a Swine Model of Coronary Slow Flow

Objective: Preliminary clinical studies have confirmed that Shexiang Tongxin dropping pills (STDPs) could improve angina pectoris and attenuate vascular endothelial dysfunction in patients with slow coronary flow, but the underlying mechanism is not fully unclear. We aimed to investigate the impact of STDP in a swine model of coronary slow flow (SF) and related mechanisms.

Methods: SF was induced by coronary injection of 40μm microspheres, and pigs were randomly divided into the SF group and SF plus STDP group. Pigs in the STDP group received sublingual STDP for 10 min, followed by 1 g STDP oral administration daily for 6 days. Coronary angiography was performed, the TIMI frame count (TFC) was determined, and hemodynamic measurements were performed before, at 30 min, and 7 days post-SF. Serum levels of total NO, NOS, ET-1, C-TNI, and BNP were measured. Myocardial expressions of TNF and IL-6, eNOS, VEGF, CD31, and α-SMA were analyzed by immunohistochemistry and Western blotting.

Results: Compared to the SF group, LVEF and TFC were significantly improved at 7 days post-SF in the STDP group. The serum ET-1 level was significantly reduced at 7 days, and NO and NOS levels were significantly higher in the STDP group. Seven days post-SF, myocardial TNF and IL-6 expressions were significantly downregulated, while the expressions of eNOS and VEGF, CD31, and ɑ-SMA were significantly upregulated in the STDP group.

Conclusion: Our results showed that STDP improved cardiac function and coronary flow, possibly through reducing inflammatory responses and upregulating myocardial eNOS and VEGF, CD31, and the ɑ-SMA expression.

A Narrative Review of the Classical and Modern Diagnostic Methods of the No-Reflow Phenomenon

The incidence of the no-reflow (NR) phenomenon varies depending on the diagnostic criteria used. If just the angiographic criteria are considered (i.e., a degree of thrombolysis in myocardial infarction ≤2), it will be found that the incidence of NR is quite low; on the other hand, when the myocardial NR is taken into account (i.e., a decrease in the quality of myocardial reperfusion expressed by the degree of myocardial blush), the real incidence is higher. Thus, the early establishment of a diagnosis of NR and the administration of specific treatment can lead to its reversibility. Otherwise, regardless of the follow-up period, patients with NR have a poor prognosis. In the present work, we offer a comprehensive perspective on diagnostic tools for NR detection, for improving the global management of patients with arterial microvasculature damage, which is a topic of major interest in the cardiology field, due to its complexity and its link with severe clinical outcomes.

Comparison of angiographic results and clinical outcomes of no-reflow after stenting in left anterior descending (LAD) versus non-LAD culprit STEMI

Objectives:

No-reflow is a complication that frequently occurs after stenting during primary percutaneous coronary intervention. In this study, we focused on angiographic results and clinical outcomes after no-reflow in the left anterior descending (LAD) artery versus non–left anterior descending artery ST-elevation myocardial infarction (STEMI).

Methods:

In this prospective study, a total of 201 patients who had developed no-reflow during primary percutaneous coronary intervention were enrolled. The patients were divided into left anterior descending artery culprit and non-left anterior descending artery culprit groups. The primary endpoints were final thrombolysis in myocardial infarction flow, corrected thrombolysis in myocardial infarction frame count and final myocardial blush grade. Secondary endpoints were major adverse cardiovascular events in-hospital and at 1 month.

Results:

Out of the 201 patients, 60.19% had culprit left anterior descending artery. Pulse rate, baseline systolic and diastolic blood pressure, single-vessel disease, left ventricular ejection fraction <30%, baseline thrombolysis in myocardial infarction I flow and final thrombolysis in myocardial infarction II flow (24.8% vs 11.3%, p = .017), and thrombolysis in myocardial infarction frame count (28.17 ± 11.86 vs 24.38 ± 9.05, p = .016) were significantly higher in the left anterior descending artery group. In contrast, baseline Killip Class I, three-vessel disease, baseline thrombolysis in myocardial infarction II flow, final thrombolysis in myocardial infarction III flow (74.4% vs 87.5%, p = .024) and left ventricular ejection fraction >40% were significantly greater in the non–left anterior descending artery group. However, for both in-hospital and at 30 days, overall major adverse cardiovascular event was similar in the two groups. The demographics, clinical and medication profiles and the routes used to treat no-reflow were all comparable in both groups.

Conclusions:

No-reflow in left anterior descending artery ST-elevation myocardial infarction is associated with lower final thrombolysis in myocardial infarction III flow, higher thrombolysis in myocardial infarction frame count and relatively lower Grade III myocardial blush than non-left anterior descending artery ST-elevation myocardial infarction with subsequent lower left ventricular ejection fraction and a higher frequency of in-hospital heart failure and hospitalisation due to heart failure.

No-reflow phenomenon and in vivo cholesterol crystals combined with lipid core in acute myocardial infarction

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The number of in vivo cholesterol crystals at the culprit plaque is increased in patients with the no-reflow phenomenon.

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The number of cholesterol crystals, lipid arch, and ostium lesion are independent predictors for the no-reflow phenomenon after PCI.

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The combination of the number of cholesterol crystals and lipid arc can improve the prediction ability for the no-reflow phenomenon.

Background

The release of lipid-laden plaque material subsequent to ST-segment elevation myocardial infarction (STEMI) may contribute to the no-reflow phenomenon. The aim of this study was to investigate the association between in vivo cholesterol crystals (CCs) detected by optical coherence tomography (OCT) and the no-reflow phenomenon after successful percutaneous coronary intervention (PCI) in patients with acute STEMI.

Methods

We investigated 182 patients with STEMI. Based on the thrombolysis in myocardial infarction (TIMI) flow grade after PCI, patients were divided into a no-reflow group (n = 31) and a reflow group (n = 151). On OCT, CCs were defined as thin, high-signal intensity regions within a plaque. A multivariable logistic regression analysis was performed to determine predictors for the no-reflow phenomenon.

Results

The prevalence of CCs was higher in the no-reflow group than the reflow group (no-reflow group, 77% vs. reflow group, 53%; p = 0.012). The multivariable logistic model showed that the CC number, lipid arc and ostial lesions were positive independent predictors of no-reflow. The combination of a lipid arc ≥ 139°and CC number ≥ 12 showed good predictive performance for the no-reflow phenomenon (sensitivity, 48%; specificity, 93%; and accuracy, 86%).

Conclusion

In vivo CCs at the culprit plaque are associated with the no-reflow phenomenon after PCI in patients with STEMI. The combination of the number of CCs and lipid arc can predict the no-reflow phenomenon after PCI with a high accuracy of 86%.

Intracoronary epinephrine and verapamil in the refractory no-reflow phenomenon in patients with acute myocardial infarction

Despite modern advances in performing percutaneous coronary interventions, refractory no-reflow remains a serious problem that worsens in-hospital and long-term prognosis. Low-dose adrenaline may exhibit potent beta-receptor agonist properties that mediate coronary vasodilation.

Aim. To evaluate the efficacy and safety of intracoronary administration of epinephrine and verapamil, as well as their combination, compared with standard treatment in patients with ST-segment elevation myocardial infarction (STEMI) and refractory no-reflow during percutaneous coronary interventions.

Material and methods. Patients with STEMI and refractory no-reflow will be randomized into 4 groups: standard therapy, intracoronary adrenaline, intracoronary verapamil, intracoronary epinephrine + verapamil. All patients will be assessed for epicardial blood flow using the Thrombolysis in Myocardial Infarction (TIMI) and Myocardial Blush Grade (MBG) scales, peak troponin levels, ST segment changes, echocardiography, magnetic roesnance imaging, and dynamic single photon emission computed tomography.

Results. Based on the pharmacodynamic effects of epinephrine and verapamil, their combination is expected to have a more potent vasodilating effect.

Conclusion. If the Intracoronary administration of EPInephrine and VERapamil in the refractory no-reflow phenomenon (EPIVER) study will be successful, a novel, more effective method for managing refractory no-reflow phenomenon will appear. This will ensure better preservation of left ventricular systolic function, as well as improve the prognosis and clinical course of the disease.

Role of NLRP3 Inflammasome in Myocardial Ischemia-Reperfusion Injury and Ventricular Remodeling

Reperfusion therapy is the optimal therapy for acute myocardial infarction (AMI), but acute inflammatory injury and chronic heart failure (HF) after myocardial ischemia and reperfusion (MI/R) remain the leading cause of death after AMI. Pyroptosis, a newly discovered form of cell death, has been proven to play a significant role in the acute reperfusion process and the subsequent chronic process of ventricular remodeling. Current research shows that multiple stimuli activate the pyroptotic signaling pathway and contribute to cell death and nonbacterial inflammation after MI/R. These stimuli promote the assembly of the nucleotide-binding and oligomerization-like receptor pyrin domain-containing protein 3 (NLRP3) inflammasome by activating NLRP3. The mature NLRP3 inflammasome cleaves procaspase-1 to active caspase-1, which leads to mature processing of interleukin (IL)-18, IL-1β, and gasdermin D (GSDMD) protein. That eventually results in cell lysis and generation of nonbacterial inflammation. The present review summarizes the mechanism of NLRP3 inflammasome activation after MI/R and discusses the role that NLRP3-mediated pyroptosis plays in the pathophysiology of MI/R injury and ventricular remodeling. We also discuss potential mechanisms and targeted therapy for which there is evidence supporting treatment of ischemic heart disease.

Mechanism and potential treatment of the "no reflow" phenomenon after acute myocardial infarction: role of pericytes and GPR39

The "no reflow" phenomenon, where the coronary artery is patent after treatment of acute myocardial infarction (AMI) but tissue perfusion is not restored, is associated with worse outcome. The mechanism of no reflow is unknown. We hypothesized that pericytes contraction, in an attempt to maintain a constant capillary hydrostatic pressure during reduced coronary perfusion pressure, causes capillary constriction leading to no reflow and that this effect is mediated through the orphan receptor, GPR39, present in pericytes. We created AMI (coronary occlusion followed by reperfusion) in GPR39 knock out mice and littermate controls. In a separate set of experiments, we treated wild-type mice undergoing coronary occlusion with vehicle or VC43, a specific inhibitor of GPR39, before reperfusion. We found that no reflow zones were significantly smaller in the GPR39 knockouts compared with controls. Both no reflow and infarct size were also markedly smaller in animals treated with VC43 compared with vehicle. Immunohistochemistry revealed greater capillary density and larger capillary diameter at pericyte locations in the GPR39-knockout and VC43-treated mice compared with controls. We conclude that GPR39-mediated pericyte contraction during reduced coronary perfusion pressure causes capillary constriction resulting in no reflow during AMI and that smaller no reflow zones in GPR39-knockout and VC43-treated animals are associated with smaller infarct sizes. These results elucidate the mechanism of no reflow in AMI, as well as providing a therapeutic pathway for the condition.NEW & NOTEWORTHY The mechanism of "no reflow" phenomenon, where the coronary artery is patent after treatment of acute myocardial infarction but tissue perfusion is not restored, is unknown. This condition is associated with worse outcome. Here, we show that GPR39-mediated pericyte contraction during reduced coronary perfusion pressure causes capillary constriction resulting in no reflow. Smaller no-reflow zones in GPR39-knockout animals and those treated with a GPR39 inhibitor are associated with smaller infarct size. These results could have important therapeutic implications.

Artery diameter ratio after recanalization in endovascular therapy for acute ischemic stroke: a new predictor of clinical outcomes

PURPOSE

This study aimed to investigate the relationship between the artery diameter ratio (ADR) after recanalization and clinical outcomes.

METHODS

Patients with middle cerebral artery occlusion confirmed by DSA from 1 January 2018, to 31 December 2019, were retrospectively analyzed. All patients confirmed TICI grade 2b or 3. The ADR was calculated as M2 segment diameter/M1 segment diameter. Multivariate regression analysis was used to describe clinical outcomes of two groups (ADR < 0.6 and ≥ 0.6). ROC curves were used to compare different models and find the best cutoff.

RESULTS

A total of 143 patients were included in the study, including 77 males and 66 females, with an average age of 67.79 ± 12 years. The NIHSS at discharge was significantly higher in the ADR < 0.6 group than another group (mean, 16.37 vs. 6.19, P < 0.001). At 90 days, the cases of functional independence was significantly less in the ADR < 0.6 group (20.97% vs. 83.95%, OR 0.05, 95% CI 0.02-0.12, P < 0.001). The ADR < 0.6 group had a higher incidence of cerebral edema (P = 0.027) and sICH (P = 0.038). The ADR had the strongest power to distinguish mRS > 2 (AUC = 0.851) and DC (AUC = 0.805), and the best cutoff value are 0.6 (specificity 85.19%, sensitivity 75.81%) and 0.58 (specificity 65.96%, sensitivity 100%), respectively.

CONCLUSION

The low ADR is associated with poor outcomes. The decrease in ADR may be an indirect manifestation of the loss of cerebrovascular autoregulation.

Controlling Reperfusion Injury With Controlled Reperfusion: Historical Perspectives and New Paradigms

Cardiac reperfusion injury is a well-established outcome following treatment of acute myocardial infarction and other types of ischemic heart conditions. Numerous cardioprotection protocols and therapies have been pursued with success in pre-clinical models. Unfortunately, there has been lack of successful large-scale clinical translation, perhaps in part due to the multiple pathways that reperfusion can contribute to cell death. The search continues for new cardioprotection protocols based on what has been learned from past results. One class of cardioprotection protocols that remain under active investigation is that of controlled reperfusion. This class consists of those approaches that modify, in a controlled manner, the content of the reperfusate or the mechanical properties of the reperfusate (e.g., pressure and flow). This review article first provides a basic overview of the primary pathways to cell death that have the potential to be addressed by various forms of controlled reperfusion, including no-reflow phenomenon, ion imbalances (particularly calcium overload), and oxidative stress. Descriptions of various controlled reperfusion approaches are described, along with summaries of both mechanistic and outcome-oriented studies at the pre-clinical and clinical phases. This review will constrain itself to approaches that modify endogenously-occurring blood components. These approaches include ischemic postconditioning, gentle reperfusion, controlled hypoxic reperfusion, controlled hyperoxic reperfusion, controlled acidotic reperfusion, and controlled ionic reperfusion. This review concludes with a discussion of the limitations of past approaches and how they point to potential directions of investigation for the future.

Accuracy of Post-thrombolysis ST-segment Reduction as an Adequate Reperfusion Predictor in the Pharmaco-Invasive Approach

Fundamento

A intervenção coronária percutânea primária é considerada o “padrão-ouro” para reperfusão coronária. Entretanto, quando não disponível, a estratégia fármaco-invasiva é método alternativo, e o eletrocardiograma (ECG) tem sido utilizado para identificar sucesso na reperfusão.

Objetivos

Nosso estudo teve como objetivo examinar alterações no segmento-ST pós-lise e seu poder de prever a recanalização, usando os escores angiográficos TIMI e blush miocárdio (MBG) como critério de reperfusão ideal.

Métodos

Foram estudados 2.215 pacientes com infarto agudo do miocárdio com supra-ST submetidos à fibrinólise [(Tenecteplase)-TNK] e encaminhados para angiografia coronária em até 24 h pós-fibrinólise ou imediatamente encaminhados à terapia de resgate. O ECG foi realizado pré-TNK e 60 min-pós. Os pacientes foram categorizados em dois grupos: aqueles com reperfusão ideal (TIMI-3 e MBG-3) e aqueles com reperfusão inadequada (fluxo TIMI <3). Foi definido o critério de reperfusão do ECG pela redução do segmento ST >50%. Consideramos p-valor <0,05 para as análises, com testes bicaudais.

Resultados

O critério de reperfusão pelo ECG apresentou valor preditivo positivo de 56%; valor preditivo negativo de 66%; sensibilidade de 79%; e especificidade de 40%. Houve fraca correlação positiva entre a redução do segmento-ST e os dados angiográficos de reperfusão ideal (r = 0,21; p <0,001) e baixa precisão diagnóstica, com AUC de 0,60 (IC-95%; 0,57-0,62).

Conclusão

Em nossos resultados, a redução do segmento-ST não conseguiu identificar com precisão os pacientes com reperfusão angiográfica apropriada. Portanto, mesmo pacientes com reperfusão aparentemente bem-sucedida devem ser encaminhados à angiografia brevemente, a fim de garantir fluxo coronário macro e microvascular adequados.

Enhancement patterns detected by multidetector computed tomography are associated with the long-term prognosis of patients with acute myocardial infarction

The present study investigated the clinical value of myocardial contrast-delayed enhancement (DE) with multidetector computed tomography (MDCT) without iodine re-injection immediately after primary percutaneous coronary intervention (PCI) for predicting future cardiovascular events after acute myocardial infarction (AMI). We performed a prospective study in which 263 consecutive patients with first AMI successfully treated with primary PCI were enrolled. Sixty-four-slice MDCT without the re-injection of contrast medium was performed immediately after PCI. Myocardial DE was considered to be transmural when involving myocardial thickness ≥ 75% (Group A; n = 104), subendocardial (< 75%, Group B; n = 108), or normal (Group C; n = 51). A semiquantitative scale score was defined for 17 left ventricular segments to investigate the extent of the DE area assessed. We examined the relationship between the presence or absence of transmural DE and long-term cardiovascular event rates. The median follow-up period was 3.5 years. Kaplan-Meier survival curves showed that patient prognosis was poorer in the group with Group A than that in the group with Group B, which was equivalent to that with Group C. A multivariate analysis identified the presence of transmural DE as the strongest predictor for future cardiovascular events (hazard ratio: 3.7; P = 0.023). Transmural myocardial DE immediately following primary PCI without an iodine re-injection for AMI is a major risk factor for future cardiovascular events.

Predictors of no-reflow phenomenon following percutaneous coronary intervention for ST-segment elevation myocardial infarction

OBJECTIVES

No reflow during percutaneous coronary intervention (PCI) is a complex issue with serious outcomes. Multiple studies have studied predictors of no-reflow during primary PCI, but data on patients with the late presentation is sparse, which constitutes the majority of patients in peripheral centers. This study aimed to determine predictors of no-reflow during PCI in patients with ST-segment elevation myocardial infarction (STEMI) in 7 days.

METHODS

It was a single-center prospective case-control study performed at a tertiary care center and included 958 patients with STEMI who underwent PCI within 7 days of symptom onset. Baseline and angiographic data of patients undergoing PCI were recorded and patients divided into reflow and no-reflow group.

RESULTS

Of 958 who underwent PCI, 182 (18.9%) showed no-reflow by myocardial blush grade (MBG)<2. No-reflow group had a higher mean age (66.46±10.71 vs. 61.36±9.94 years), lower systolic blood pressure (SBP) on admission (100.61±26.66 vs. 112.23±24.35, P<0.0001), a higher level of peak Troponin I level (9.37±2.81 vs. 7.66±3.11ng/dL, P<0.0001), low left ventricular ejection fraction (36.71±3.89 vs. 39.58±4.28% respectively P<0.0001). Among angiographic data and procedural features, multivariable logistic regression analysis identified that advanced age, reperfusion time>6hours, SBP<100mmHg on admission, functional status of Killip class for heart failure≥3, lower EF (≤35%), low initial myocardial blush grade (≤1) before PCI, long target lesion length, larger reference diameter of vessel (>3.5mm) and high thrombus burden on angiography were found to be independent predictors of no-reflow (P<0.05).

CONCLUSION

No-reflow phenomenon after PCI for STEMI is complex and multifactorial and can be identified by simple clinical, angiographic, and procedural features. Preprocedural characters of the lesion and early perfusion decides the fate of the outcome.

Systematic Understanding of Pathophysiological Mechanisms of Oxidative Stress-Related Conditions-Diabetes Mellitus, Cardiovascular Diseases, and Ischemia-Reperfusion Injury

Reactive oxygen species (ROS) plays a role in intracellular signal transduction under physiological conditions while also playing an essential role in diseases such as hypertension, ischemic heart disease, and diabetes, as well as in the process of aging. The influence of ROS has some influence on the frequent occurrence of cardiovascular diseases (CVD) in diabetic patients. In this review, we considered the pathophysiological relationship between diabetes and CVD from the perspective of ROS. In addition, considering organ damage due to ROS elevation during ischemia-reperfusion, we discussed heart and lung injuries. Furthermore, we have focused on the transient receptor potential (TRP) channels and L-type calcium channels as molecular targets for ROS in ROS-induced tissue damages and have discussed about the pathophysiological mechanism of the injury.

The outcomes in STEMI patients with high thrombus burden treated by deferred versus immediate stent implantation in primary percutaneous coronary intervention: a prospective cohort study

Background

No-/slow-reflow indicates worse outcomes in ST-elevation myocardial infarction (STEMI) patients with high thrombus burden. We examined whether deferred stenting (DS) strategy reduces no-/slow-reflow or major adverse cardiovascular events (MACEs) in primary percutaneous coronary intervention (pPCI) for patients with acute STEMI and high thrombus burden.

Methods

We performed an open-label, multi-center, prospective cohort study among eligible patients with acute STEMI and high thrombus burden who further received pPCI. All participants received PCI with DS (second procedure performed within 48-72 h) or immediate-stenting (IS) strategy. The primary outcome was the incidence of no-/slow-reflow. We evaluated MACEs and bleeding events during hospitalization and at 30- and 90-day follow-ups.

Results

We recruited 245 patients to this study, including 51 with DS and 194 with IS. Baseline clinical characters were comparable between the 2 strategies. Incidence of no-/slow-reflow defined by thrombolysis in myocardial infarction (TIMI) flow grade was not significantly different between the 2 strategies [DS: 5 (9.8%), IS: 33 (17.0%), P=0.21]. No-/slow-reflow by TIMI myocardial perfusion grade (TMPG) was less prevalent in DS [20 (39.2%) vs. 107 (55.2%), P=0.04]. No significant differences were found in recurrence of myocardial infarction (P=0.56), cardiac death (P=0.37), all-cause mortality (P=0.37), heart failure-induced readmission (P=0.35), or bleeding (P=0.61) between the 2 strategies in-hospital, and at 30- and 90-day follow-up.

Conclusions

In STEMI patients with high thrombus burden who underwent pPCI, DS strategy reduced no-/slow-reflow of microcirculation. However, DS strategy did not reduce incidence of MACEs or bleeding.

Low Ankle-Brachial Index is Associated with Microvascular Coronary Obstruction After Primary PCI

Introduction

Percutaneous coronary intervention (PCI) has improved recanalization of infarct-related arteries (IRA); however, TIMI-III flow does not always mean an efficient myocardial reperfusion. Myocardial blush grade (MBG) is used as a predictor for coronary microvascular obstruction. We assessed the association between ankle-brachial index (ABI), a widely used method for diagnosis of peripheral arterial disease (PAD), and coronary microvascular obstruction (MVO) as detected by MBG after primary PCI.

Patients and Methods

The study included 335 patients with ST-elevation myocardial infarction who had primary PCI. History taking, clinical examination, laboratory assessment, ECG and Echocardiography were done for every participant. MBG was assessed for patients after PCI procedure. ABI for all participating patients was calculated.

Results

Two hundred and sixty-one patients fulfilled the inclusion criteria with mean age 58.8 ± 10.7 years, 84% were males. Sixty-one percent had anterior wall myocardial infarction. After primary PCI, despite achieving TIMI flow III in all study patients, only 37% had normal MBG. There was a statistically significant relationship between MBG and site of infarction, left ventricular ejection fraction and ABI. Low ABI was found to predict poor MBG.

Conclusion

Coronary artery disease (CAD) is well linked to PAD. MBG can be used to assess coronary MVO after primary PCI. Poor MBG is associated with low ABI. This could establish a relationship between PAD and coronary MVO after primary PCI.

Metformin attenuates ischemia/reperfusion-induced apoptosis of cardiac cells by downregulation of p53/microRNA-34a via activation of SIRT1

Metformin has been demonstrated to be beneficial for the treatment of an impaired myocardium as a result of ischemia/reperfusion (I/R) injury, and miR-34a may be involved in this process. The aim of the present study was to determine the mechanisms by which metformin attenuated myocardial I/R injury-induced apoptosis. In the in vivo I/R model using Sprague-Dawley rats, metformin reduced the area of damaged myocardium and serum creatine MB isoform (CKMB) activity resulting in protection of the myocardium. Metformin also reduced apoptosis and the expression of apoptosis associated proteins, including caspase 3 and cleaved caspase, and decreased the expression of miR-34a, which is upregulated during I/R injury, which in turn resulted in corresponding changes in expression of Bcl-2, a direct target of miR-34a both in vitro and in vivo. To further examine the role of miR-34a in this process, H9C2 cells were transfected by a miR-34a mimic and inhibitor. Overexpression of miR-34a increased apoptosis in H9C2 cells induced by oxygen-glucose deprivation/recovery and knockdown of miR-34a expression-reduced apoptosis under the same conditions. Therefore, the effect of metformin on miR-34a in vitro were assessed. Metformin decreased the deacetylation activity of silent information regulator 1 resulting in reduced Ac-p53 levels, which reduced the levels of pri-miR-34a, and thus in turn reduced miR-34a levels. To confirm these results clinically, 90 patients with ST-segment elevation myocardial infarction following percutaneous coronary intervention were recruited. Patients who took metformin regularly before infarction had lower miR-34a levels and lower serum CKMB activity. Metformin also improved the sum ST-segment recovery following I/R injury. In conclusion, metformin may be helpful in the treatment of myocardial I/R.

Prognostic value of initial QRS analysis in anterior STEMI: Correlation with left ventricular systolic dysfunction, serum biomarkers, and cardiac outcomes

BACKGROUND

The presence of pathologic Q waves on admission electrocardiogram (ECG) in patients with anterior ST-elevated myocardial infarction (STEMI) has been related to adverse cardiac outcomes. Our study evaluates the prognostic value of QRS complex and Q waves in patients with STEMI undergoing percutaneous coronary intervention.

METHODS

We prospectively analyzed the specific characteristics of QRS complex and pathologic Q waves on admission and on discharge ECG in 144 patients hospitalized for anterior STEMI. We correlated these findings with the development of left ventricular systolic dysfunction (LVSD), appearance of heart failure (HF) or death during follow-up, and levels of several biomarkers obtained 6 months after the index event.

RESULTS

Multivariate logistic regression analysis showed that QRS width (odds ratios [OR] 1.05, p = .001) on admission ECG and the sum of Q-wave depth (OR 1.06, p = .002) on discharge ECG were independent predictors of LVSD development. Moreover, QRS width on admission ECG was related to an increased risk of HF or death (OR 1.03, p = .026). Regarding biomarkers, QRS width on admission ECG revealed a statistically significant relationship with the levels of NT-pro-BNP at 6 months (0.29, p = .004); the sum of Q-wave depth (0.27, p = .012) and width (0.25, p = .021) on admission ECG was related to the higher levels of hs-cTnI; the sum of the voltages in precordial leads both on admission ECG (-0.26, p = .011) and discharge ECG (0.24, p = .046) was related to the lower levels of parathormone.

CONCLUSIONS

Assessment of QRS complex width and pathologic Q waves on admission and discharge ECGs aids in predicting long-term prognosis in patients with STEMI.

No-Reflow after PPCI-A Predictor of Short-Term Outcomes in STEMI Patients

The no-reflow phenomenon following primary percutaneous coronary intervention (PPCI) in acute ST-elevation myocardial infarction (STEMI) patients is a predictor of unfavorable prognosis. Patients with no-reflow have many complications during admission, and it is considered a marker of short-term mortality. The current research emphasizes the circumstances of the incidence and complications of the no-reflow phenomenon in STEMI patients, including in-hospital mortality. In this case-control study, conducted over two and a half years, there were enrolled 656 patients diagnosed with STEMI and reperfused through PPCI. Several patients (n = 96) developed an interventional type of no-reflow phenomenon. One third of the patients with a no-reflow phenomenon suffered complications during admission, and 14 succumbed. Regarding complications, the majority consisted of arrhythmias (21.68%) and cardiogenic shock (16.67%). The anterior localization of STEMI and the left anterior descending artery (LAD) as a culprit lesion were associated with the highest number of complications during hospitalization. At the same time, the time interval >12 h from the onset of the typical symptoms of myocardial infarction (MI) until revascularization, as well as multiple stents implantations during PPCI, correlated with an increased incidence of short-term complications. The no-reflow phenomenon in patients with STEMI was associated with an unfavorable short-term prognosis.

A Scoring System to Predict No-Reflow Phenomenon in Elective Percutaneous Coronary Intervention: The RECOVER Score

The RECOVER score system aimed to stratify the risk of no-reflow phenomenon in patients undergoing elective percutaneous coronary intervention. A total of 3967 patients with 5340 lesions were used for the construction and validating of the risk model and score system. In multivariable analyses, 3 variables were independently associated with the risk of no-reflow phenomenon (model C-statistic=0.746 (95% confidence interval [CI]: 0.690 to 0.803) with good calibration). No-reflow phenomenon rates in both construction and validation cohort increased significantly across different risk groups. The RECOVER score can help identify patients at risk for phenomenon during percutaneous coronary intervention.

Imaging the injured beating heart intravitally and the vasculoprotection afforded by haematopoietic stem cells

Aims

Adequate microcirculatory perfusion, and not just opening of occluded arteries, is critical to salvage heart tissue following myocardial infarction. However, the degree of microvascular perfusion taking place is not known, limited primarily by an inability to directly image coronary microcirculation in a beating heart in vivo. Haematopoietic stem/progenitor cells (HSPCs) offer a potential therapy but little is known about their homing dynamics at a cellular level and whether they protect coronary microvessels. This study used intravital microscopy to image the anaesthetized mouse beating heart microcirculation following stabilization.

Methods and results

A 3D-printed stabilizer was attached to the ischaemia–reperfusion injured (IRI) beating heart. The kinetics of neutrophil, platelet and HSPC recruitment, as well as functional capillary density (FCD), was imaged post-reperfusion. Laser speckle contrast imaging (LSCI) was used for the first time to monitor ventricular blood flow in beating hearts. Sustained hyperaemic responses were measured throughout reperfusion, initially indicating adequate flow resumption. Intravital microscopy confirmed large vessel perfusion but demonstrated poor transmission of flow to downstream coronary microvessels. Significant neutrophil adhesion and microthrombus formation occurred within capillaries with the latter occluding them, resulting in patchy perfusion and reduced FCD. Interestingly, ‘patrolling’ neutrophils were also observed in capillaries. Haematopoietic stem/progenitor cells readily trafficked through the heart but local retention was poor. Despite this, remarkable anti-thromboinflammatory effects were observed, consequently improving microvascular perfusion.

Conclusion

We present a novel approach for imaging multiple microcirculatory perturbations in the beating heart with LSCI assessment of blood flow. Despite deceptive hyperaemic responses, increased microcirculatory flow heterogeneity was seen, with non-perfused areas interspersed with perfused areas. Microthrombi, rather than neutrophils, appeared to be the major causative factor. We further applied this technique to demonstrate local stem cell presence is not a pre-requisite to confer vasculoprotection. This is the first detailed in vivo characterization of coronary microcirculatory responses post-reperfusion injury.

All-cause mortality and the risk of stroke with selective aspiration thrombectomy in patients with ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention: A nationwide retrospective cohort study

Few data exist on the clinical outcomes of selective aspiration thrombectomy during primary percutaneous coronary intervention (PPCI).This was a nationwide retrospective cohort study. Patients who were diagnosed with ST-elevation myocardial infarction (STEMI) and received primary percutaneous coronary intervention (PCI) from July 2009 to December 2011 were identified from the National Health Insurance Research Database of Taiwan. Propensity score weighting was used to balance the covariates between the 2 study groups. The primary endpoints were all-cause mortality and stroke during hospitalization and at 30 days and 1 year of follow-up. Subgroup analyses were performed based on the hospital and physician volume of primary PCI.A total of 9100 ST-elevation myocardial infarction patients (29.4% of patients receiving aspiration thrombectomy and conventional PPCI vs 70.6% receiving PPCI alone) were identified. The incidence rates of all-cause mortality were comparable between the 2 groups during hospitalization (21.0 vs 27.37/100 person-months; P = .29) and 1-year follow-up (0.81 vs 1.26/100 person-months; P = .85). There were no significant differences in the stroke rates between the 2 groups during hospitalization (1.1 vs 2.34/100 person-months; P = .3) and 1-year follow-up (0.09 vs 0.15/100 person-months; P = .85). For the patients who survived to discharge, the post-discharge 1-year mortality was lower in the aspiration thrombectomy group of patients in whom the procedures were performed by physicians with a high volume of PPCI (hazard ratio: 0.47; 95% confidence interval: 0.24-0.94; P = .03).In this nationwide cohort study, selective aspiration thrombectomy at the operation's discretion had a comparable mortality rate compared with PCI alone and did not increase the risk of stroke. In the patients treated by physicians with a high volume of PPCI, aspiration thrombectomy appeared to have a beneficial effect on post-discharge survival at 1 year.

Assessment of Growth Differentiation Factor 15 Levels on Coronary Flow in Patients with STEMI Undergoing Primary PCI

Growth Differentiation Factor-15 (GDF-15) is a strong predictor of decreased myocardial salvage and subsequent higher risk of death in patients with STEMI, but no information has been published regarding the association of GDF-15 levels with coronary blood flow in STEMI. We hypothesized that elevated GDF-15 levels would be associated with impaired flow and perfusion in the setting of STEMI treated with primary PCI. Eighty consecutive patients who were admitted with STEMI within 6 h from symptom onset were enrolled in the study. Patients were divided into two groups based upon the Thrombolysis in Myocardial Infarction (TIMI) flow grade. Group 1 was defined as TIMI Grade 0, 1 and 2 flows. Angiographic success was defined as TIMI 3 flow (group 2). GDF-15 and high sensitive CRP were measured. Major adverse cardiac events (MACE) were defined as stent thrombosis, nonfatal myocardial infarction and in-hospital mortality. There were 35 patients (mean age 64 ± 11.8 and 20% female) in group 1 and 45 patients (mean age 66.8 ± 11.5 and 29% female) in group 2. GDF-15 and hs-CRP levels were significantly higher in group 1 than in group 2 (1670 ± 831pg/mL vs. 733 ± 124 pg/mL, p < 0.001; and 19.8 ± 10.6 vs. 11.3 ± 4.9, p < 0.001). GDF-15 level ≥920 pg/mL measured on admission had a 94% sensitivity and 91% specificity in predicting no-reflow at ROC curve analysis. In-hospital MACE was also significantly higher in group 1 (28.6% vs. 2.2%, p: 0.001). Additionally, there was a significant correlation between hs-CRP and GDF-15 (r: 0.6030.56; p < 0.001). The GDF-15 level on admission is a strong and independent predictor of poor coronary blood flow following primary PCI and in hospital MACE among patients with STEMI. Except for predictive value, GDF-15 levels may be a useful biomarker for the stratification of risk in patients with STEMI, and may carry further therapeutic implications.

Predictive values of D-dimer for the long-term prognosis of acute ST-segment elevation infarction: A retrospective study in southwestern China

D-dimer is a primary degradation product of cross-linked fibrin, and can be an effective diagnostic factor of venous thromboembolism. However, its prognostic role in patients with acute ST-segment elevation myocardial infarction (STEMI) remains controversial. This study aimed to investigate whether D-dimer has a predictive value for long-term prognosis in patients with STEMI.We retrospectively enrolled 872 STEMI patients treated with primary percutaneous coronary intervention. Patients were divided into quartiles according to their admission D-dimer increased multiple, with the highest quartile (G4) (n = 219) defined as increased multiple ≧1.33, and the lowest quartile (G1) (n = 215) as increased multiple ≦0.33.Compared with G1, higher in-hospital heart failure (40.2% vs 10.2%, P < .0001), malignant arrhythmia (14.2% vs 2.3%, P < .0001), and all-cause mortality (5.9% vs 0%, P < .0001) rates were observed in G4. After a follow-up period of 29 months, 84 patients had died. In the Cox multivariate analysis, a high admission D-dimer increased multiple (≧1.33) was found to be an independent predictor of all-cause mortality (hazards ratio: 2.53, 95% confidence interval: 1.02-6.26, P = .045).Thus, there was an association between a high D-dimer level and the increase in in-hospital major adverse cardiovascular events, such as heart failure, malignant arrhythmias, and death. High D-dimer level was also an independent predictor of long-term all-cause mortality.

Sonoreperfusion therapy for microvascular obstruction: A step toward clinical translation

Sonoreperfusion therapy is being developed as an intervention for the treatment of microvascular obstruction. We investigated the reperfusion efficacy of two clinical ultrasound systems (a modified Philips EPIQ and a Philips Sonos 7500) in a rat hindlimb microvascular obstruction model. Four ultrasound conditions were tested using 20 min treatments: Sonos single frame, Sonos multi-frame, EPIQ low pressure and EPIQ high pressure. Contrast-enhanced perfusion imaging of the microvasculature was conducted at baseline and after treatment to calculate microvascular blood volume (MBV). EPIQ high pressure treatment resulted in significant recovery of MBV from microvascular obstruction, returning to baseline levels after treatment. EPIQ low pressure and Sonos multi-frame treatment resulted in significantly improved MBV after treatment but below baseline levels. Sonos single-frame and control groups showed no improvement post-treatment. This study demonstrates that the most effective sonoreperfusion therapy occurs at high acoustic pressure coupled with high acoustic intensity. Moreover, a clinically available ultrasound system is readily capable of delivering these effective therapeutic pulses.

Incidence, Predictors, and Prognosis of Coronary Slow-Flow and No-Reflow Phenomenon in Patients with Chronic Total Occlusion Who Underwent Percutaneous Coronary Intervention

Background

The incidence and prognosis of coronary slow-flow (CSF) and no-reflow phenomenon (NRP) in patients with coronary chronic total occlusion (CTO) who underwent percutaneous coronary intervention (PCI) remain unclear.

Methods

This single-center prospective study aimed to investigate the incidence of CSF/NRP during CTO interventional therapy, determine predictors of CSF/NRP, and evaluate its effect on patient outcomes.

Results

In this study, 552 patients with CTO who underwent PCI were included. CSF/NRP occurred in 16.1% of them. They had higher incidences of diabetes mellitus (53.9% vs 36.3%, p=0.002) and hypertension (50.6% vs 37.1%, p=0.018) and a lower incidence of retrograde filling grade >2 (34.8% vs 47.1%, p=0.036). Patients with CSF/NRP had a higher neutrophil ratio (55.6±19.4 vs 52.4±18.3, p=0.038) and levels of low-density lipoprotein (LDL; 3.0±0.8 vs 2.8±0.6, p=0.029), fasting glucose (FG; 8.3±1.3 vs 6.8±1.1, p=0.005), uric acid (332.6±82.9 vs 308.2±62.8, p=0.045), and high-sensitivity C-reactive protein (Hs-CRP; 9.8±4.8 vs 7.3±3.9, p=0.036). A multivariate logistic regression analysis revealed that diabetes mellitus (odds ratio [OR], 1.962; 95% confidence interval [CI]: 1.198–2.721; p=0.042), mean platelet volume (MPV; OR,1.284; 95% CI, 1.108–1.895; p=0.046), LDL cholesterol (LDL-C; OR, 1.383; 95% CI, 1.105–2.491; p=0.036), FG (OR, 2.095; 95% CI, 1.495–2.899; p=0.018), Hs-CRP(OR, 2.218; 95% CI, 1.556–3.519; p=0.029), and retrograde filling of grade >2 (OR, 0.822; 95% CI, 0.622–0.907; p=0.037) were independent predictors of CSF/NRP in CTO patients who underwent PCI. Kaplan-Meier analysis revealed that the patients in the CSF/NRP group had a significantly lower cumulative major cardiac and cerebrovascular events (MACCE)-free survival than those in the non-CSF/NRP group (p<0.0001).

Conclusion

Of the patients with CTO who underwent PCI, 16.1% developed CSF/NRP and had a significantly lower cumulative MACCE-free survival rate. Diabetes mellitus; higher levels of MPV, LDL-C, FG, and Hs-CRP; and a lower incidence of retrograde filling grade >2 were independent predictors of CSF/NRP in CTO patients who underwent PCI. Thus, they can be used for risk stratification.

Incidence, predictors and outcomes of stress hyperglycemia in patients with ST elevation myocardial infarction undergoing primary percutaneous coronary intervention

BACKGROUND

Stress hyperglycemia is a common finding during ST elevation myocardial infarction in diabetic patients and is associated with a worse outcome. However, there are limited data about stress hyperglycemia in non-diabetic patients and its outcome especially in patients undergoing primary percutaneous coronary intervention.

METHODS

The study was conducted on 660 patients with ST elevation myocardial infarction who were managed with primary percutaneous coronary intervention. Patients were classified into two groups according to the presence of stress hyperglycemia: group I (patients with stress hyperglycemia) and group II (patients without stress hyperglycemia). Patients were analysed for clinical outcome including mortality and the occurrence of major adverse cardiac events.

RESULTS

Incidence of stress hyperglycemia was 16.8%, multivariate regression analysis identified the independent predictors of stress hyperglycemia, that were family history of diabetes mellitus odds ratio 1.697 (95% confidence interval: 1.077-2.674, p = 0.023), body mass index >24 kg/m² odds ratio 1.906 (95% confidence interval: 1.244-2.922, p = 0.003) and cardiogenic shock on admission odds ratio 2.517 (95% confidence interval: 1.162-5.451, p = 0.019). Mortality, cardiogenic shock, contrast induced nephropathy and no reflow phenomenon were significantly higher in stress hyperglycemia group with p value = 0.027, 0.001, 0.020 and 0.037, respectively.

CONCLUSION

Stress hyperglycemia in non-diabetic patients with ST elevation myocardial infarction undergoing primary percutaneous coronary intervention is associated with increased incidence of no reflow phenomenon, contrast induced nephropathy, cardiogenic shock and higher mortality.

Relationship between the ST-Segment Resolution and Microvascular Dysfunction in Patients Who Underwent Primary Percutaneous Coronary Intervention

Objectives

Incomplete ST-segment elevation resolution (STR) occasionally occurs despite successful revascularization of epicardial coronary artery after primary percutaneous coronary intervention (PPCI). The aim of this study was to evaluate the relationship between the degree of STR and the severity of microvascular dysfunction.

Methods

A total of 73 consecutive patients with ST-segment elevation myocardial infarction (STEMI) who underwent successful PPCI were evaluated. Serial 12-lead electrocardiography was performed at baseline and at 90 minutes after PPCI. Microvascular dysfunction was assessed by index of microvascular resistance (IMR) immediately after PPCI.

Results

Patients were classified into 2 groups: 50 patients with complete STR (STR ≥50%) and 23 patients with incomplete STR (STR <50%). The incomplete STR group had a higher IMR value and lower left ventricular ejection fraction (LVEF), compared with the complete STR group. The degree of STR was significantly correlated with IMR (r = −0.416, P=0.002) and LVEF (r = 0.300, P=0.011). These correlations were only observed in patients with left anterior descending artery (LAD) infarction but not observed in patients with non-LAD infarction. A cutoff IMR value was 27.3 for predicting incomplete STR after PPCI.

Conclusion

Incomplete STR after PPCI in patients with STEMI reflects the presence of microvascular and left ventricular dysfunction, especially in patients with LAD infarction.