Coronary no-reflow phenomenon

No-Reflow Prediction in Acute Coronary Syndrome During Percutaneous Coronary Intervention: The NORPACS Risk Score

BACKGROUND

Suboptimal coronary reperfusion (no reflow) is common in acute coronary syndrome percutaneous coronary intervention (PCI) and is associated with poor outcomes. We aimed to develop and externally validate a clinical risk score for angiographic no reflow for use following angiography and before PCI.

METHODS

We developed and externally validated a logistic regression model for prediction of no reflow among adult patients undergoing PCI for acute coronary syndrome using data from the Melbourne Interventional Group PCI registry (2005-2020; development cohort) and the British Cardiovascular Interventional Society PCI registry (2006-2020; external validation cohort).

RESULTS

A total of 30 561 patients (mean age, 64.1 years; 24% women) were included in the Melbourne Interventional Group development cohort and 440 256 patients (mean age, 64.9 years; 27% women) in the British Cardiovascular Interventional Society external validation cohort. The primary outcome (no reflow) occurred in 4.1% (1249 patients) and 9.4% (41 222 patients) of the development and validation cohorts, respectively. From 33 candidate predictor variables, 6 final variables were selected by an adaptive least absolute shrinkage and selection operator regression model for inclusion (cardiogenic shock, ST-segment-elevation myocardial infarction with symptom onset >195 minutes pre-PCI, estimated stent length ≥20 mm, vessel diameter <2.5 mm, pre-PCI Thrombolysis in Myocardial Infarction flow <3, and lesion location). Model discrimination was very good (development C statistic, 0.808; validation C statistic, 0.741) with excellent calibration. Patients with a score of ≥8 points had a 22% and 27% risk of no reflow in the development and validation cohorts, respectively.

CONCLUSIONS

The no-reflow prediction in acute coronary syndrome risk score is a simple count-based scoring system based on 6 parameters available before PCI to predict the risk of no reflow. This score could be useful in guiding preventative treatment and future trials.

Effects of RAAS blocker use on AKI in elderly hypertensive STEMI patients with propensity score weighed method

Studies reported conflicting results on the effect of renin-angiotensin-aldosterone system (RAAS) blocker use on acute kidney injury (AKI) in patients undergoing elective coronary angiography but association in elderly patients with ST-elevation myocardial infarction (STEMI) is not known. Also, there are limited data on the effect of inflammatory markers on AKI. We aimed to investigate the effects of RAAS blocker pretreatment and inflammatory markers on AKI in this population. A total of 471 patients were compared according to presence of RAAS blocker pretreatment at admission. Conventional and inverse probability weighed conditional logistic regression were used to determine independent predictors of AKI. Mean age of the study group was 75.4 ± 7.1 years and 29.1% of the patients were female. AKI was observed in 17.2% of the study population. Weighted conditional multivariable logistic regression analysis revealed that AKI was associated with baseline creatinine levels and C-reactive protein/albumin ratio (CAR) (OR 2.08, 95% CI = 1.13-3.82, p = .02 and OR 1.19, 95% CI = 1.01-1.41, p = .04, respectively). No significant association was found between RAAS blocker pretreatment and AKI. CAR and elevated baseline creatinine levels were independent predictors of AKI in this patient group.

CRP Albumin Ratio May Predict No Reflow in Patients Undergoing Percutaneous Coronary Intervention for Saphenous Vein Graft Stenosis

Many hypotheses have been proposed to explain no-reflow (NR). Some of these hypotheses, state that NR may be caused by damage to the vascular endothelium and an inflammatory process. In a recent study that did not include patients with coronary artery bypass graft (CABG), the ratio of C-reactive protein (CRP) to albumin (CAR) was found to be associated with NR. Our study aims to evaluate the relationship between CAR and NR in patients who underwent percutaneous coronary intervention (PCI) for saphenous vein graft (SVG). In this retrospective study, among the patients with CABG who underwent primary or elective coronary angiography, 242 patients who underwent PCI to the SVG were selected. The incidence of NR was 19.8% (n = 48). Diabetes mellitus, left ventricular ejection fraction (LVEF), stent length, and CAR were found as independent predictors of NR in multivariate logistic regression analysis (P < .05). Using a cut-off level of .930, the CAR predicted NR with a sensitivity of 75% and a specificity of 73% (AUC: .814, 95% CI: .749-.879, P < .001). The CAR was a better predictor than both stent length and LVEF. CAR was found to be the strongest predictor of NR in our study.

Association of ectatic non-infarct-related artery with 1-month stent thrombosis in patients with ST elevation myocardial infarction

BACKGROUND

Ectatic infarct-related artery (IRA) has been shown to be associated with higher thrombus burden, no-reflow, stent thrombosis (ST) and major adverse cardiovascular events in patients with ST-elevation myocardial infarction (STEMI). The effect of ectatic non-IRA on ST without ectatic IRA is not known. We aimed to assess the effect of ectatic non-IRA presence on ST within 1 month after primary percutaneous intervention (pPCI) in patients with STEMI.

METHODS

A total of 1541 patients with a diagnosis of STEMI and underwent pPCI between 2015 and 2020 were retrospectively included in the study. Patients with and without 1 month ST were compared. Penalised logistic regression method was used to assess the association between ST and candidate predictors due to the risk of overfitting.

RESULTS

Median age of the study group was 56.5 (48.7 to 67.2) years. The Synergy between PCI with Taxus and Cardiac Surgery (SYNTAX) score, ectatic non-IRA presence and use of tirofiban were significantly higher in the ST group (18.2±9.9 vs 15.1±9.9, p=0.03; 25% vs 7.2%, p<0.001; 54.2% vs 30.5%, p<0.001; respectively). Significantly higher thrombus aspiration (14.3% vs 6.7%, p=0.03) and lower stent implantation (67.7% vs 84%, p<0.001) rates were observed in ectatic IRA group compared with ectatic non-IRA group. In multivariable analysis, ectatic non-IRA presence was independently associated with 1-month ST (OR 4.01, 95% CI 1.86 to 8.63, p=0.01).

CONCLUSION

Ectatic non-IRA presence without ectatic IRA in patients with STEMI increases the risk of ST within the first month of pPCI.

Time course of coronary flow capacity impairment in ST-segment elevation myocardial infarction

BACKGROUND

Microvascular dysfunction in the setting of ST-elevated myocardial infarction (STEMI) plays an important role in long-term poor clinical outcome. Coronary flow reserve (CFR) is a well-established physiological parameter to interrogate the coronary microcirculation. Together with hyperaemic average peak flow velocity, CFR constitutes the coronary flow capacity (CFC), a validated risk stratification tool in ischaemic heart disease with significant prognostic value. This mechanistic study aims to elucidate the time course of the microcirculation as reflected by alterations in microcirculatory physiological parameters in the acute phase and during follow-up in STEMI patients.

METHODS

We assessed CFR and CFC in the culprit and non-culprit vessel in consecutive STEMI patients at baseline (n = 98) and after one-week (n = 64) and six-month follow-up (n = 65).

RESULTS

A significant trend for culprit CFC in infarct size as determined by peak troponin T (p = 0.004), time to reperfusion (p = 0.038), the incidence of final Thrombolysis In Myocardial Infarction 3 flow (p = 0.019) and systolic retrograde flow (p = 0.043) was observed. Non-culprit CFC linear contrast analysis revealed a significant trend in C-reactive protein (p = 0.027), peak troponin T (p < 0.001) and heart rate (p = 0.049). CFC improved both in the culprit and the non-culprit vessel at one-week (both p < 0.001) and six-month follow-up (p = 0.0013 and p < 0.001) compared with baseline.

CONCLUSION

This study demonstrates the importance of microcirculatory disturbances in the setting of STEMI, which is relevant for the interpretation of intracoronary diagnostic techniques which are influenced by both culprit and non-culprit vascular territories. Assessment of non-culprit vessel CFC in the setting of STEMI might improve risk stratification of these patients following coronary reperfusion of the culprit vessel.

Acute alterations in glucose homeostasis impact coronary microvascular function in patients presenting with ST-segment elevation myocardial infarction

Background

Microvascular dysfunction in the setting of ST-segment myocardial infarction (STEMI) is thought to be related to stress-related metabolic changes, including acute glucose intolerance. The aim of this study was to assess the relationship between admission glucose levels and microvascular function in non-diabetic STEMI patients.

Methods

92 consecutive patients with a first anterior-wall STEMI treated with primary percutaneous coronary intervention (PPCI) were enrolled. Blood glucose levels were determined immediately prior to PPCI. After successful PPCI, at 1‑week and 6‑month follow-up, Doppler flow was measured in culprit and reference coronary arteries to calculate coronary flow velocity reserve (CFVR), baseline (BMR) and hyperaemic (HMR) microvascular resistance.

Results

The median admission glucose was 8.3 (7.2–9.6) mmol/l respectively 149.4 mg/dl [129.6–172.8] and was significantly associated with peak troponin T (standardised beta coefficient [std beta] = 0.281; p = 0.043). Multivariate analysis revealed that increasing glucose levels were significantly associated with a decrease in reference vessel CFVR (std beta = −0.313; p = 0.002), dictated by an increase in rest average peak velocity (APV) (std beta = 0.216; p = 0.033), due to a decreasing BMR (std beta = −0.225; p = 0.038) in the acute setting after PPCI. These associations disappeared at follow-up. These associations were not found for the infarct-related artery.

Conclusion

Elevated admission glucose levels are associated with impaired microvascular function assessed directly after PPCI in first anterior-wall STEMI. This influence of glucose levels is an acute phenomenon and contributes to microvascular dysfunction through alterations in resting flow and baseline microvascular resistance.

Serum cystatin C levels relate to no-reflow phenomenon in percutaneous coronary interventions in ST-segment elevation myocardial infarction

Background/Aim

No-reflow is a serious and frequent event during primary percutaneous coronary intervention (PPCI) for acute ST segment elevation myocardial infarction (STEMI). The aim of this study was to identify possible predictors for no-reflow.

Patients and methods

We investigated 218 patients with acute anterior STEMI who underwent PPCI from December 2016 to December 2018. No-reflow was defined as a coronary TIMI flow grade of ≤ 2. TIMI flow grade 3 was defined as normal reflow.

Results

In our study, the no-reflow phenomenon was observed in 39 patients (18%) during angiography. The patients of no-reflow group were found to be more older, diabetics, longer pain-to-balloon time, lower blood pressure, higher platelet counts and higher levels of D-Dimer and Cystatin C (Cys-C). In multivariate logistic regression analysis, only diabetes (OR = 0.371, 95% CI: 0.157–0.872, P = 0.023), longer pain-to-balloon time (OR = 1.147, 95% CI: 1.015–1.297, P = 0.028) and higher Cys-C level (OR = 10.07, 95% CI: 2.340–43.377, P = 0.002) were predictors for no-reflow.

Conclusion

Cys-C might be a useful predictor for the no-reflow phenomenon after PPCI in STEMI patients. It might help to screen STEMI patients with high risk of no-reflow on admission.

To Whom Thrombus Aspiration May Concern?

BACKGROUND

Thrombus aspiration for ST-segment elevation myocardial infarction (STEMI) may improve myocardial perfusion. However, these favourable results called into a question by data indicating not only a lack of efficacy but a risk of potentially deleterious complications.

AIM

To assess the effect of thrombus aspiration during the primary percutaneous coronary intervention (PPCI) on procedural angiographic results, stent characteristics, and major adverse cardiac and cerebrovascular events (MACCE).

METHODS

All consecutive STEMI patients candidate for PPCI and admitted to Critical Care Department, Cairo University hospitals, managed either by thrombectomy before primary PCI (if thrombus score ≥ 3) or conventional PPCI, Six hundred seven subjects were enrolled in the study divided into Group with thrombectomy before PPCI (107 subjects, 18%), and group with Conventional PCI (500 subjects, 82%). ST-segment resolution, peak CK-MB, TIMI score, thrombus score, and MBG were assessed; stent number, diameter, length and stented segment were reported and follow up MACCE was reported (in hospital and 1-year post-intervention).

RESULTS

Mean values for peak CKMB were less in thrombectomy group (228 ± 174 I/U vs 269 ± 186 I/U, p = 0.04), ST segment resolution ≥ 70% occurred in {63 subjects (58.9%) vs 233 (46.6%), p = 0.001} in thrombectomy vs conventional group respectively. TIMI score pre procedure was zero in (102 subjects (95%) vs 402 (80.4%), p = 0.001), while TIMI III post procedure was reported in (100 subjects (93.4%) vs 437 (87%), p = 0.06), MBG mean values were (2.4 ± 0.6 vs 2.0 ± 1, p = 0.001), thrombus score was higher in thrombectomy group (4.6 ± 0.4 vs 0.8 ± 1.7, p = 0.001) in thrombectomy vs conventional group respectively. Direct stenting was { 34 patients (31%) vs 102 patients (20%), p = 0.05}, mean stent diameter (2.7 ± 1.3 mm vs 3.5 ± 1.3 mm, p = 0.3), mean stent length was (19.9 mm ± 10 versus 22.7 mm ± 8 in p 0.01). mean stent number was (1.0 ± 0.5 vs 1.2 ± 0.6, p = 0.001), mean stented segment was (22.5 ± 13.5 vs 28.5 ± 15.2 mm, p = 0.001) in thrombectomy vs conventional group respectively. MACCE in hospital were reported in {9 subjects (8.4%) vs 70 (14%), p = 0.07)}. Follow up MACCE after 1 year reported in {6 subjects (5.6 %) vs 80 (16 %), p 0.= 4} in thrombectomy vs conventional group respectively.

CONCLUSION

Thrombus aspiration before primary PCI (in a selected group with thrombus score ≥ 3) improves myocardial perfusion, suggested by better ST-segment resolution, TIMI flow, less peak CKMB and MBG, associated with a higher rate of direct stenting, shorter stent length, stented segments and less number of stents. Although thrombus aspiration was done in more risky patients (higher thrombus score) MACCE (in hospital and 1 year follow up) showed no statistical difference.

Relation of hemoglobin level to no-reflow in patients with ST-segment elevation myocardial infarction undergoing primary coronary intervention

Introduction

The primary goal in the management of acute ST segment elevation myocardial infarction (STEMI) is to open the occluded artery at an early stage. The development of no-reflow is multifactorial, and the etiology is not fully understood. There is accumulating evidence that anemia is related to a series of severe complications in cardiovascular disease (CVD) such as thromboembolic events, bleeding complications, uncontrolled hypertension, and inflammation characterized by elevated levels of inflammatory cytokines.

Aim

We investigated the relationship between hemoglobin level and the no-reflow of infarct-related artery (IRA) in patients with STEMI undergoing primary percutaneous coronary intervention (PPCI).

Material and methods

A total of 3804 patients with acute STEMI who underwent PPCI were enrolled. The patients were divided into two groups according to thrombolysis in myocardial infarction (TIMI) flow grades after PPCI. Hematological parameters were measured on admission. Univariate and multivariate logistic regression analyses were conducted to assess the association between hemoglobin level and no-reflow.

Results

In the current study, 471 (12.4%) patients presented with no-reflow after PPCI. The patients in the no-reflow group had a significantly lower hemoglobin level (12.1 ±1.9 g/dl vs. 13.8 ±1.8 g/dl, p < 0.001). The multivariate logistic regression models revealed that hemoglobin level (OR = 0.564, 95% CI: 0.526–0.605; p < 0.001) was an independent predictor of development of no-reflow. The cutoff value for hemoglobin level was 11.5 g/dl with sensitivity of 83.0% and specificity of 80.0% (AUC = 0.844, 95% CI: 0.821–0.867; p < 0.001).

Conclusions

Our results suggest that hemoglobin level showed a moderate diagnostic performance regarding the prediction of no-reflow in patients with STEMI undergoing PPCI.

Intracoronary adenosine versus intravenous adenosine during primary PCI for ST-elevation myocardial infarction: which one offers better outcomes in terms of microvascular obstruction?

Aims. Previous studies have suggested that intravenous administration of adenosine improves myocardial reperfusion and reduces infarct size in ST-elevation myocardial infarction (STEMI) patients. Intracoronary administration of adenosine has shown conflicting results. Methods. In this retrospective, single-centre, blinded clinical study, we assessed whether selective intracoronary administration of adenosine distal to the occlusion site immediately before initial balloon inflation reduces microvascular obstruction (MVO) as assessed with cardiac magnetic resonance imaging (MRI). Using contrast-enhanced sequences, microvascular obstruction (MVO) was calculated. We found 81 patients presenting with STEMI within 12 h from symptom onset who were eligible for the study. In 80/81 (100%) patients receiving the study drug, MRI was performed on Day 1 after primary angioplasty. Results. The prevalence of MVO was reduced in the patients treated with intracoronary adenosine, (45%) compared to 85% of patients who were administered intravenous adenosine (P = 0.0043). We found that the size of MVO in patients receiving intracoronary adenosine was significantly reduced compared to 0.91 g in the intravenous-treated group (P = 0.027). There was no statistically significant difference in TIMI flow and clinical outcomes after primary PCI. Conclusion. We found significant evidence that selective high-dose intracoronary administration of adenosine distal to the occlusion site of the culprit lesion in STEMI patients results in a decrease in microvascular obstruction.

Coronary no-reflow phenomenon: from the experimental laboratory to the cardiac catheterization laboratory

Coronary no-reflow occurs commonly during acute percutaneous coronary intervention, particularly in patients with acute myocardial infarction and those with degenerated vein grafts. It is associated with a guarded prognosis, and thus needs to be recognized and treated promptly. The pathophysiology originates during the ischemic phase and is characterized by localized and diffuse capillary swelling and arteriolar endothelial dysfunction. In addition, leukocytes become activated and are attracted to the lumen of the capillaries, exhibit diapedesis and may contribute to cellular and intracellular edema and clogging of vessels. At the moment of perfusion, the sudden rush of leukocytes and distal atheroemboli further contributes to impaired tissue perfusion. Shortening the door-to-balloon time, use of glycoprotein IIb/IIIa platelet receptor inhibitors and distal protection devices are predicted to limit the development of no-reflow during percutaneous interventions. Distal intracoronary injection of verapamil, nicardipine, adenosine, and nitroprusside may improve coronary flow in the majority of patients. Hemodynamic support of the patient may be needed in some cases until coronary flow improves.