Predictors of suboptimal coronary blood flow after primary angioplasty and its implications on short-term outcomes in patients with acute anterior STEMI

Clinical characteristics and outcomes of Australian and Indian ST-segment elevation myocardial infarction (STEMI) patients treated with primary percutaneous coronary intervention (PCI)

INTRODUCTION

The incidence of STEMI and subsequent mortality has been reported to be higher in Indian populations compared to developed countries. However, there is limited data directly comparing contemporary primary percutaneous coronary intervention (pPCI) treatment strategies and clinical outcomes for STEMI patients between developed and developing countries.

MATERIALS AND METHODS

We compared population demographics, procedural characteristics, times to reperfusion and mortality in STEMI patients treated with pPCI between two tertiary referral centers in India and Australia respectively over a 3-year period (1st Jan 2017-31st Dec 2019).

RESULTS

A total of 1293 STEMI presentations (896 Indian vs 397 Australian) were included. On average, Indian patients had lower median BMI than Australian patients (BMI 25.4 vs 27.8; p < 0.001), were significantly younger (mean age 56.0 vs 63.2 years; p < 0.001), more likely male (84 % vs 80 %; p = 0.046) and diabetic (48 % vs 18 %); p < 0.001). Radial access (50 % vs 88 %; p < 0.001) and TIMI III flow post PCI was also significantly lower (85 % vs 96 %; p < 0.001) with median door-to-balloon time significantly shorter in the Indian cohort (20mins vs 43mins; p < 0.001); however, median symptom to balloon time was significantly longer (245mins vs 160mins; p < 0.001). No significant differences in 30-day mortality (4.0 % vs 2.8 % Australian; p = 0.209) or 1-year mortality (6.5 % vs 4.3 %; p = 0.120) were observed.

CONCLUSION

Significant differences in demographics and presentation characteristics exist between Indian and Australian STEMI patients treated with pPCI. Indian patients had significantly longer pre-hospital delays and lower achievement of TIMI III flow post PCI, yet shorter in-hospital time to treatment.

Reduction of left ventricular diastolic pressure as a key regulator of infarct coronary flow under mechanical left ventricular support

Restoring ischaemic myocardial tissue perfusion is crucial for minimizing infarct size. Acute mechanical left ventricular (LV) support has been suggested to improve infarct tissue perfusion. However, its regulatory mechanism remains unclear. We investigated the physiological mechanisms in six Yorkshire pigs, which were subjected to 90-min balloon occlusion of the left anterior descending artery. During the acute reperfusion phase, LV support using an Impella heart pump was initiated. LV pressure, coronary flow and pressure of the infarct artery were simultaneously recorded to evaluate the impact of LV support on coronary physiology. Coronary wave intensity was calculated to understand the forces regulating coronary flow. Significant increases in coronary flow velocity and its area under the curve were found after mechanical LV support. Among the coronary flow-regulating factors, coronary pressure was increased mainly during the late diastolic phase with less pulsatility. Meanwhile, LV pressure was reduced throughout diastole resulting in significant and consistent elevation of coronary driving pressure. Interestingly, the duration of diastole was prolonged with LV support. In the wave intensity analysis, the duration between backward suction and pushing waves was extended, indicating that earlier myocardial relaxation and delayed contraction contributed to the extension of diastole. In conclusion, mechanical LV support increases infarct coronary flow by extending diastole and augmenting coronary driving pressure. These changes were mainly driven by reduced LV diastolic pressure, indicating that the key regulator of coronary flow under mechanical LV support is downstream of the coronary artery, rather than upstream. Our study highlights the importance of LV diastolic pressure in infarct coronary flow regulation. KEY POINTS: Restoring ischaemic myocardial tissue perfusion is crucial for minimizing infarct size. Although mechanical left ventricular (LV) support has been suggested to improve infarct coronary flow, its specific mechanism remains to be clarified. LV support reduced LV pressure, and elevated coronary pressure during the late diastolic phase, resulting in high coronary driving pressure. This study demonstrated for the first time that mechanical LV support extends diastolic phase, leading to increased infarct coronary flow. Future studies should evaluate the correlation between improved infarct coronary flow and resulting infarct size.

In search for "healthy" landing zones for coronary stent placement: are the largest intrasegmental lumens adequate?

Background

Coronary lesions are supposed to be enclosed between proximal and distal reference segments (RSs), the sites with the largest lumens within the same vessel segment. Finding "healthy" landing zones has been fundamental for efficient stent implantation. Consequently, our study aimed to determine, using optical coherence tomography (OCT), to what degree RSs conform to this concept.

Methods

Sixty-seven patients with a mean age of 63.5 years underwent culprit lesion stenting due to acute myocardial infarction (MI) (Group 1) or stable angina (Group 2). OCT was performed with commercially available equipment; all evaluations were made at RSs and minimal lumens.

Results

Normal vessel wall was infrequent (~10%) at RSs. Acceptable external elastic 220°) occurred in 55% to 67% and in 28% to 31% of RSs, respectively. Tissue composition at RSs was similar in both study groups except for a greater accumulation of thin-cap fibroatheromas (TCFA) in acute MI (29% in Group 1 vs. 9% in Group 2, P=0.035). Flow deterioration after stenting was associated with TCFA clusters extending from culprit main bodies into proximal RSs (P=0.008).

Conclusions

Optimal landing zones for stent placement should frequently be searched for beyond the culprit lesion segments although utilizing the largest intrasegmental lumens does not seem to cause immediate harm. However, TCFA at the landings should definitely be avoided.

Factors of Hospital Mortality in Men and Women with ST-Elevation Myocardial Infarction - An Observational, Retrospective, Single Centre Study

Purpose

There are well-known gender differences in mortality of patients with ST-elevation myocardial infarction (STEMI). Our purpose was to assess factors of hospital mortality separately for men and women with STEMI, which are less well known.

Patients and Methods

In 2018-2019, 485 men and 214 women with STEMI underwent treatment with primary percutaneous coronary intervention (PCI). We retrospectively compared baseline characteristics, treatments and hospital complications between men and women, as well as between nonsurviving and surviving men and women with STEMI.

Results

Primary PCI was performed in 94% of men and 91.1% of women with STEMI, respectively. The in-hospital mortality was significantly higher in women than in men (14% vs 8%, p=0.019). Hospital mortality in both genders was associated significantly to older age, heart failure, prior resuscitation, acute kidney injury, to less likely performed and less successful primary PCI and additionally in men to hospital infection and in women to bleeding. In men and women ≥65 years, mortality was similar (13.3% vs 17.8%, p = 0.293).

Conclusion

Factors of hospital mortality were similar in men and women with STEMI, except bleeding was more likely observed in nonsurviving women and infection in nonsurviving men.

Impact of age on pre-procedural TIMI flow in STEMI patients undergoing primary percutaneous coronary intervention

BACKGROUND

Advanced age is a major determinant of impaired prognosis among patients with ST-segment elevation myocardial infarction (STEMI). However, the mechanisms associated with suboptimal reperfusion and enhanced complications are still largely undefined. The aim of the present study was to assess the impact of age on the angiographic findings and the procedural results of primary percutaneous coronary intervention (pPCI) in patients with STEMI.

METHODS

A consecutive cohort of patients admitted for STEMI treated with pPCI were included. Infarct-related artery (IRA) patency was defined for preprocedural TIMI flow 3.

RESULTS

We included 520 patients, divided according to age tertiles (<61; 61-72; ≥73). Elderly patients were more often females, with hypertension, renal failure, prior myocardial infarction or PCI, with lower rates of smoking history, haemoglobin, leukocytes and cholesterol (P < 0.001), lower ejection fraction (P = 0.02), higher use of renin angiotensin system inhibitors, statins, ASA, calcium antagonists, diuretics and beta blockers. At angiography, for the IRA, percentage of thrombus (P = 0.02) and stenosis (P = 0.01), direct stenting (P = 0.02) and glycoprotein IIb-IIIa inhibitors (P = 0.04) inversely related with age, but for higher restenosis (P = 0.04). IRA patency was more common in patients aged ≥73 years (27.9% vs. 32.3% vs. 41.1%, P = 0.01). The impact of age on preprocedural TIMI flow was confirmed at multivariate analysis [adjusted odds ratio (95% confidence interval) = 0.68 (0.47-0.98), P = 0.04].

CONCLUSION

The present study shows that among STEMI patients undergoing primary PCI, more advanced age represents an independent predictor of preprocedural IRA patency. Future studies will define the implications on procedural results and long-term prognosis.

Risk Factors of Suboptimal Coronary Blood Flow after a Percutaneous Coronary Intervention in Patients with Acute Anterior Wall Myocardial Infarction

BACKGROUND AND AIMS

Primary percutaneous coronary intervention (PCI) is regarded as the most preferred strategy in ST-segment elevation myocardial infarction (STEMI). Thrombolysis in Myocardial Infarction (TIMI) flow grade has been an important and cohesive predictor of outcomes in STEMI patients. We sought to evaluate potential variables associated with the risk of suboptimal TIMI flow after PCI in patients with anterior wall STEMI.

METHODS

We evaluated 107 patients admitted to our hospital between 1 January 2019 and 31 December 2021 with a diagnosis of anterior wall STEMI treated with primary PCI.

RESULTS

Suboptimal TIMI flow grade (≤2) after PCI occurred in 14 (13%) patients while grade 3 was found in 93 (87%) of them presenting with anterior wall STEMI. Failure to achieve optimal TIMI 3 flow grade after PCI was associated with lower TIMI grade prior to PCI (OR 0.5477, 95% CI 0.2589-0.9324, p = 0.02), greater troponin concentration before (OR 1.0001, 95% CI 1-1.0001, p = 0.0028) and after PCI (OR 1.0001, 95% CI 1-1.0001, p = 0.0452) as well as lower mean minimal systolic blood pressure (OR 0.9653, 95% CI 0.9271-0.9985, p = 0.04).

CONCLUSIONS

Among predictors of suboptimal TIMI flow grade after PCI, we noted lower TIMI grade flow pre-PCI, greater serum troponin concentrations in the periprocedural period and lower mean minimal systolic blood pressure.

Clinical and Angiographic Predictors of suboptimal Coronary Flow After Primary Percutaneous Coronary Intervention in Patients with ST-Elevation Myocardial Infarction

INTRODUCTION

This study aimed to investigate the clinical and angiographic characteristics of patients with ST-elevation myocardial infarction who experienced primary percutaneous coronary intervention failure.

METHOD

This retrospective observational study was derived from the Primary Angioplasty Registry of Sina Hospital (PARS). A total of 548 consecutive patients with ST-elevation myocardial infarction who underwent primary percutaneous coronary intervention between November 2016 and January 2019 were evaluated. Percutaneous coronary intervention failure was defined as Thrombolysis in Myocardial Infarction (TIMI) flow ≤ 2 or corrected TIMI frame count (cTFC) ≥ 28.

RESULTS

The study population consisted of 458 (83.6%) males and 90 (16.4%) females with a mean age of 59.2 ± 12.49 years. TIMI flow 3 was achieved in 499 (91.1%) patients after the procedure, while 49 (8.9%) patients developed TIMI ≤ 2. The findings showed that cTFC ≥ 28 was present in 50 (9.1%) patients, while 489 (89.2%) patients had cTFC < 28. Multiple regression analysis shows that age 1.04 (1.01, 1.07), duration of pain onset to first medical contact time 1.04 (1.00, 1.18), and left anterior descending artery involvement 3.15 (1.21, 8.11) were independent predictors of TIMI ≤ 2.

CONCLUSION

Even though TIMI ≤ 2 was uncommon among the study population, it was associated with adverse in-hospital outcomes. The results indicate that earlier emergency medical service arrival and shorter transfer time to the referral center can dramatically reduce the primary percutaneous coronary intervention failure rate.

An exploration of the early discharge approach for low-risk STEMI patients following primary percutaneous coronary intervention

Recently, there has been growing interest in the early discharge strategy for low-risk patients who have undergone primary percutaneous coronary intervention (PCI) to treat ST-segment elevation myocardial infarction (STEMI). So far findings have suggested there are multiple advantages of shorter hospital stays, including that it could be a safe way to be more cost- and resource-efficient, reduce cases of hospital-acquired infection and boost patient satisfaction. However, there are remaining concerns surrounding safety, patient education, adequate follow-up and the generalisability of the findings from current studies which are mostly small-scale. By assessing the current research, we describe the advantages, disadvantages and challenges of early hospital discharge for STEMI and discuss the factors that determine if a patient can be considered low risk. If it is feasible to safely employ a strategy like this, the implications for healthcare systems worldwide could be extremely beneficial, particularly in lower-income economies and when we consider the detrimental impacts of the recent COVID-19 pandemic on healthcare systems.

Initial experience with a continuous mechanical aspiration system for thrombus removal before percutaneous coronary intervention

OBJECTIVES

Here we investigate the safety and efficacy of a continuous mechanical aspiration system when used before percutaneous coronary intervention (PCI) in patients with acute coronary syndrome (ACS).

BACKGROUND

Historically, trials of routine manual aspiration thrombectomy in ACS patients have reported mixed results. This may be due to the technical limitations of manual aspiration, which suffers from decreasing vacuum power as aspiration is performed.

METHODS

This is a retrospective case series of all patients treated with continuous mechanical aspiration (Indigo CAT RX Aspiration System; Penumbra Inc.) before PCI between August 2017 and July 2020 at five centers in the United States. Data regarding angiographic assessments, procedure, and safety were examined.

RESULTS

Seventy-two patients (mean age 60 ± 12.5 years, 34.7% female) with ST Elevation Myocardial Infarction (STEMI) (80.6%) or Non-ST Elevation Myocardial Infarction (NSTEMI) (19.4%) were included. Target vessels were the right coronary (43.1%), left anterior descending (33.3%), and left circumflex (23.6%). Preprocedure, 94.4% had a high thrombus burden (thrombolysis in myocardial infarction [TIMI] thrombus grade ≥ 3). Median aspiration time was 35 s and median access-to-reperfusion time was 10 min. After CAT RX alone, 86.1% had complete perfusion (TIMI flow grade 3). After the procedure, 94.4% had TIMI thrombus grade <3% and 97.2% had TIMI flow grade 3. There were no cases of ischemic stroke. Cardiovascular mortality at 30 days was 1.4%.

CONCLUSIONS

In our initial experience, aspirating thrombus from ACS patients using the Indigo CAT RX Aspiration System before PCI was safe and effective for reducing thrombus burden and restoring flow.

Impact of hyperuricemia on coronary blood flow and in-hospital mortality in patients with acute myocardial infarction undergoing percutaneous coronary intervention

BACKGROUND

Although serum uric acid (UA) is considered as a risk factor for cardiovascular disease, few data exist regarding the relationship between hyperuricemia, coronary blood flow, and subsequent outcome in patients with acute myocardial infarction (AMI). The purpose of our study is to assess whether hyperuricemia is associated with suboptimal coronary flow and increased risk of mortality in patients with AMI after percutaneous coronary intervention (PCI).

METHODS

Using the Rural AMI registry data, 989 consecutive patients with AMI who underwent emergent PCI and had UA measurement at admission were analyzed. We defined hyperuricemia as serum UA ≥7.0 mg/dL in men and ≥ 6.0 mg/dL in women. The primary endpoint was suboptimal coronary flow, defined as post PCI Thrombosis In Myocardial Infarction flow grade ≤ 2. The secondary outcome was in-hospital mortality.

RESULTS

Hyperuricemia was found in 249 (25.2%) patients. Patients with hyperuricemia were more often complicated with cardiogenic shock compared with those without (16.9% vs. 7.4%, p < 0.001). In addition, the median high-sensitivity C-reactive protein was significantly higher in patients with hyperuricemia (0.18 mg/dL; IQR, 0.09-0.71 mg/dL) than in those without (0.14 mg/dL; IQR, 0.07-0.41 mg/dL, p < 0.05). Under these conditions, the prevalence of suboptimal coronary flow after PCI (17.3% vs. 10.1%, p < 0.05) and in-hospital mortality (10.8% vs. 3.6%, p < 0.001) were significantly higher in patients with hyperuricemia compared with those without. Multivariable logistic regression analysis revealed that hyperuricemia was significantly associated with suboptimal coronary flow [odds ratio (OR), 1.60; 95% confidence interval (CI), 1.02-2.49; p < 0.05] and in-hospital mortality (OR, 2.08; 95% CI, 1.05-4.12; p < 0.05).

CONCLUSIONS

Assessment of serum UA upon admission provides useful information for predicting suboptimal coronary flow and in-hospital mortality in patients with AMI undergoing PCI.

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.

Comparison of door-to-balloon time and in-hospital outcomes in patients with ST-elevation myocardial infarction between before versus after COVID-19 pandemic

The situation around primary percutaneous coronary intervention (PCI) has dramatically changed since coronavirus disease 2019 (COVID-19) pandemic. The impact of COVID-19 pandemic on clinical outcomes as well as door-to-balloon time (DTBT), which is known as one of the indicators of early reperfusion, has not been fully investigated in patients with ST-elevation acute myocardial infarction (STEMI). The purpose of this study was to compare DTBT and in-hospital outcomes in patients with STEMI between before versus after COVID-19 pandemic. The primary interest was DTBT and the incidence of in-hospital outcomes including in-hospital death. We included 330 patients with STEMI who underwent primary PCI, and divided them into the pre COVID-19 group (n = 209) and the post COVID-19 group (n = 121). DTBT was significantly longer in the post COVID-19 group than in the pre COVID-19 group (p < 0.001), whereas the incidence of in-hospital death was comparable between the 2 groups (p = 0.238). In the multivariate logistic regression analysis, chest CT before primary PCI (OR 4.64, 95% CI 2.58-8.34, p < 0.001) was significantly associated with long DTBT, whereas chest CT before primary PCI (OR 0.76, 95% CI 0.29-1.97, p = 0.570) was not associated with in-hospital death after controlling confounding factors. In conclusion, although DTBT was significantly longer after COVID-19 pandemic than before COVID-19 pandemic, in-hospital outcomes were comparable between before versus after COVID-19 pandemic. This study suggests the validity of the screening tests including chest CT for COVID-19 in patients with STEMI who undergo primary PCI.

Predictors and 3-year outcomes of compromised left circumflex coronary artery after left main crossover stenting

BACKGROUND

There are few predictors of decreased fractional flow reserve (FFR) in the left circumflex coronary artery (LCx) after left main (LM) crossover stenting.

OBJECTIVES

We aimed to determine the predictors for low FFR at LCx and possible treatment strategies for compromised LCx, together with their long-term outcomes.

METHODS

Altogether, 563 patients who met the inclusion criteria were admitted to our hospital from February 2015 to November 2020 with significant distal LM bifurcation lesions. They underwent single-stent crossover percutaneous coronary intervention (PCI) under intravascular ultrasound (IVUS) guidance with further LCx intervention based on the measured FFR.

RESULTS

The patients showed significant angiographic LCx ostial affection post-LM stenting, but only 116 (20.6%) patients had FFR < 0.8. The three-year composite major adverse cardiac events (MACE) rates were comparable between the high and low FFR groups (16.8% vs. 15.5; p = 0.744). In a multivariate analysis, low FFR at the LCx was associated with post-stenting minimal luminal area (MLA) of LCx (odds ratio [OR]: 0.032, p < .001), post-stenting LCx plaque burden (OR: 1.166, p < .001), poststenting LM MLA (OR: 0.821, p = .038), and prestenting LCx MLA (OR: 0.371, p = .044). In the low FFR group, those with compromised LCx managed with drug-eluting balloon had the lowest three-year MACE rate (8.1%), as compared to either those undergoing kissing balloon inflation (KBI) (17.5%) or stenting (20.5%) (p = 0.299).

CONCLUSION

Unnecessary LCx interventions can be avoided with FFR-guided LCx intervention. Poststenting MLA and plaque burden of the LCx, and main vessel stent length are poststenting predictors of low FFR.

The ATRIA and Modified-ATRIA Scores in Evaluating the Risk of No-Reflow in Patients With STEMI Undergoing Primary Percutaneous Coronary Intervention

The no-reflow (NR) phenomenon is frequently encountered in acute coronary syndrome. We evaluated the association between anticoagulation and risk factors in atrial fibrillation (ATRIA) and modified ATRIA risk scores and NR in ST-elevation myocardial infarction (STEMI). Consecutive patients (n = 551) who underwent primary percutaneous coronary intervention between December 2019 and June 2020 due to STEMI were included. The mean age of the patients was 60.5 ± 10.8 years (n = 369, 67% male). The ATRIA and modified anticoagulation and risk factors in atrial fibrillation-hyperlipidemia, smoking, male (m-ATRIA-HS) scores were calculated. The NR group had higher frequency of diabetes mellitus (DM), serum creatine kinase-MB (CK-MB) levels, and corrected thrombolysis in myocardial infarction frame count (cTFC) (P = .002, P = .006, and P < .001, respectively). In regression analysis, ATRIA, m-ATRIA-HS, thrombus grade, and cTFC were independent predictors of NR. Age, higher CK-MB, and neutrophil-to-lymphocyte ratio and DM were the other predictors for NR. Pairwise comparison of receiver operating characteristics curve analysis showed that the m-ATRIA-HS (>2, area under curve [AUC]: 0.715) has better performance than ATRIA score (>1, AUC: 0.656), with a P < .022 and z statistics 2.279. In conclusion, ATRIA, especially the m-ATRIA-HS, can be used to evaluate NR risk in STEMI.