Impact of coronary artery collaterals on infarct size assessed by serial cardiac magnetic resonance imaging after primary percutaneous coronary intervention in patients with acute myocardial infarction

Do collaterals to infarct bed in STE-ACS patients undergoing emergent percutaneous coronary revascularization matter? An assessment of a prospective pool for in-hospital course

BACKGROUND

Limited data exist on the role of coronary collaterals circulation (CCC) in patients with ST-elevation acute coronary syndrome (STE-ACS). This study aimed to assess CCC and the in-hospital course of patients with CCC undergoing primary percutaneous coronary intervention (pPCI).

METHODS

The study included consecutive STE-ACS patients undergoing pPCI. Good CCC was defined as Rentrop collateral score (RCS) of 2-3. Patients with good and poor CCC were compared regarding clinical characteristics, angiographic patterns, and hospital course.

RESULTS

In the sample of 4683 patients, mean age was 55.6 ± 11 years, and 78.8 % were male. Good CCC was observed in 499 (10.7 %) patients. The rate of intra-procedure slow-flow/no-reflow (SF/NR) was 29.9 % vs. 20.5 % (p < 0.001), and the rate of composite adverse clinical outcomes (CACO) was 21.2 % vs. 19 % (p = 0.225) for patients with good and poor CCC, respectively. Multivariable analysis identified left ventricular end-diastolic pressure (LVEDP), multi-vessel disease (MVD), and thrombus grade ≥4 as independent predictors of good CCC, with adjusted odds ratios of 0.98 [0.97-0.99], 1.69 [1.35-2.10], and 3.45 [2.64-4.52], respectively. In propensity-matched cohorts, the intra-procedure SF/NR rate was 29.9 % vs. 26.9 % (p = 0.292), and the rate of CACO was 21.2 % vs. 23.4 % (p = 0.403) for patients with good and poor CCC, respectively.

CONCLUSION

Angiographic evidence of good CCC in STE-ACS patients was limited. Good CCC was associated with a higher prevalence of MVD, high thrombus burden, and low pre-procedure LVEDP, resulting in a higher incidence of intra-procedure SF/NR. However, the CACO did not differ significantly between patients with good and poor CCC.

Association of Coronary Collaterals and Myocardial Salvage Measured by Serial Cardiac Magnetic Resonance Imaging after Acute Myocardial Infarction

BACKGROUND

Coronary collateral flow in angiography has been linked with lower mortality rates in patients with coronary artery disease. However, the relevance of the underlying mechanism is sparse. Therefore, we tested the hypothesis that in patients with acute myocardial infarction (AMI), relevant coronary collateral flow is associated with more salvaged myocardium and lower risk of developing heart failure.

METHODS AND RESULTS

Patients with first AMI who received a percutaneous coronary intervention within 24 h after symptom onset were classified visually by assigning a Cohen-Rentrop Score (CRS) ranging between 0 (no collaterals) and 3 (complete retrograde filling of the occluded vessel). All 36 patients included in the analysis underwent cardiac magnetic resonance examination within 3 to 5 days after myocardial infarction and after 12 weeks. Patients with relevant collateral flow (CRS 2-3) to the infarct-related artery had significantly smaller final infarct size compared to those without (7 ± 4% vs. 20 ± 12%, p < 0.001). In addition, both groups showed improvement in left ventricular ejection fraction early after AMI, whereas the recovery was greater in CRS 2-3 (+8 ± 5% vs. +3 ± 5%, p = 0.015).

CONCLUSION

In patients with first AMI, relevant collateral flow to the infarct-related artery was associated with more salvaged myocardium at 12 weeks, translating into greater improvement of systolic left ventricular function. The protective effect of coronary collaterals and the variance of infarct location should be further investigated in larger studies.

N-terminal pro-brain natriuretic peptide and coronary collateral formation in patients undergoing primary percutaneous coronary intervention

There is insufficient information on the relationship between the N-terminal pro-brain natriuretic peptide (NT-proBNP) level and collateral circulation (CC) formation after primary percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction. We analyzed 857 patients who underwent primary PCI. The serum NT-proBNP levels were measured on the day of admission, and the CC was scored according to Rentrop’s classification. Log-transformed NT-proBNP levels were significantly higher in patients with good CC compared to those with poor CC (6.13 ± 2.01 pg/mL versus 5.48 ± 1.97 pg/mL, p < 0.001). The optimum cutoff value of log NT-proBNP for predicting CC was 6.04 pg/mL. Log NT-proBNP ≥ 6.04 pg/mL (odds ratio 2.23; 95% confidence interval 1.51–3.30; p < 0.001) was an independent predictor of good CC. CC development was higher in patients with a pre-TIMI flow of 0 or 1 than those with a pre-TIMI flow of 2 or 3 (22.6% versus 8.8%, p = 0.001). The incidence of left ventricular (LV) dysfunction (< 50%) was greater in patients with a pre-TIMI flow of 0 or 1 (49.8% versus 35.5%, p < 0.001). The release of NT-proBNP was greater in patients with LV dysfunction (34.3% versus 15.6%, p < 0.001). The incidence of good CC was greater in patients with log NT-proBNP levels ≥ 6.04 pg/ml (16.8% versus 26.2%, p = 0.003). The association between NT-proBNP and collateral formation was not influenced by pre-TIMI flow and LV function. NT-proBNP appears to reflect the degree of collateral formation in the early phase of STEMI and might have a new role as a useful surrogate biomarker for collateral formation in patients undergoing primary PCI.

Early recruitment of coronary collateral circulation: impact in late presentation nonreperfused acute coronary occlusion

BACKGROUND

Debate still remains on whether the presence of early recruited collateral circulation (ERCC) in the setting of an acute coronary occlusion (ACO) has a prognosis benefit. Some previous reports have shown lower mortality and morbidity rates in well-collateralized patients compared with those with poorly recruited collateral circulation (PCC), but others have not. In the primary angioplasty era, the role of collateral circulation in these studies may have been influenced by the effect of early reperfusion. The actual impact of ERCC in ACO can be clarified by studying its effect on nonreperfused patients.

OBJECTIVE

This study aimed to compare the 1-year clinical outcome in nonreperfused late presentation ACO in a major coronary artery with ERCC versus PCC.

PATIENTS AND METHODS

Between 2008 and 2015, we included 164 patients with a nonreperfused late presentation ACO. The patients were divided according to the presence of angiographic ERCC (Rentrop 2-3) or PCC (Rentrop 0-1). ERCC was present in 54% of patients. Patients with ERCC less often presented with cardiogenic shock (P=0.02) and the right coronary artery was the most frequent culprit vessel (P=0.02). The presence of PCC was associated independently with higher 1-year cardiovascular mortality [hazard ratio (HR): 6.92; 95% confidence interval (95%CI): 1.37-34.7; P=0.019], 1-year total mortality (HR: 5.79; 95%CI: 1.95-17.1; P=0.001), and 1-year major adverse cardiac event (HR: 8.05; 95%CI: 1.73-37.4; P<0.01).

CONCLUSION

The presence of angiographically PCC in the setting of late presentation nonreperfused ACO is relatively infrequent (46%) and is associated with worse 1-year major clinical outcomes.

Influence of Cardiovascular Risk Factors, Comorbidities, Medication Use and Procedural Variables on Remote Ischemic Conditioning Efficacy in Patients with ST-Segment Elevation Myocardial Infarction

Remote ischemic conditioning (RIC) confers cardioprotection in patients with ST-segment elevation myocardial infarction (STEMI). Despite intense research, the translation of RIC into clinical practice remains a challenge. This may, at least partly, be due to confounding factors that may modify the efficacy of RIC. The present review focuses on cardiovascular risk factors, comorbidities, medication use and procedural variables which may modify the efficacy of RIC in patients with STEMI. Findings of such efficacy modifiers are based on subgroup and post-hoc analyses and thus hold risk of type I and II errors. Although findings from studies evaluating influencing factors are often ambiguous, some but not all studies suggest that smoking, non-statin use, infarct location, area-at-risk of infarction, pre-procedural Thrombolysis in Myocardial Infarction (TIMI) flow, ischemia duration and coronary collateral blood flow to the infarct-related artery may influence on the cardioprotective efficacy of RIC. Results from the on-going CONDI2/ERIC-PPCI trial will determine any clinical implications of RIC in the treatment of patients with STEMI and predefined subgroup analyses will give further insight into influencing factors on the efficacy of RIC.

Prognostic value of coronary collaterals in patients with acute coronary syndromes

BACKGROUND

The presence of good coronary collateral circulation (CCC) can protect and preserve myocardium from ischemia, increase myocardial contractility, and reduce adverse clinical events. However, its impact on mortality is still a topic of debate, particularly in acute coronary syndrome (ACS). The aim of this study was to investigate the association of CCC with cardiac risk factors and in-hospital mortality in patients hospitalized with a diagnosis of ACS.

METHODS

The study population included 2286 patients with ACS who underwent coronary angiography and were found to have at least 90% significant lesion in at least one major coronary artery. The CCC was graded according to the Rentrop classification. The patients were classified into a poor CCC group (Rentrop grades 0-1, n=1859) or a good CCC group (Rentrop grades 2-3, n=427).

RESULTS

Patients with good CCC had more high-risk patient characteristics such as older age, higher rate of Killip class of at least 2 at admission, lower left ventricular ejection fraction, and impaired renal functions compared with the patients with poor CCC. In multivariate analysis, the presence of good CCC [odds ratio (OR): 2.000; 95% confidence interval: 1.116-3.585; P=0.020], left ventricular ejection fraction less than 40% (OR: 2.381; P=0.003), Killip class of at least 2 at admission (OR: 3.609; P<0.001), age of at least 65 years (OR: 2.975; P=0.003), and hemoglobin (OR: 0.797; P=0.003) were independent predictors of in-hospital mortality.

CONCLUSION

In contrast to previous studies, our study did not confirm a beneficial role of good CCC in patients with ACS; the presence of good CCC was even independently associated with increased in-hospital mortality in the multivariate analysis.

Impact of Coronary Collaterals on Long-term Prognosis in Patients Treated With Primary Angioplasty

INTRODUCTION AND OBJECTIVES

The beneficial effect of coronary collateral circulation (CC) in patients with ST-segment elevation myocardial infarction is controversial. The aim of this study was to evaluate the impact of CC before reperfusion with primary angioplasty (PA) on the long-term prognosis of these patients.

METHODS

Retrospective observational study of a cohort of 947 patients treated with PA and TIMI grade ≤ 1 flow in a single center from 2005 to 2013. Propensity score matching was used to create 2 groups of 175 patients each, matched by the degree of CC (Rentrop 0-1 vs Rentrop 2-3). In the matched cohort, we determined the impact of CC on total mortality, cardiovascular mortality, and a combined adverse cardiovascular event endpoint for a median follow-up of 864 (interquartile range, 396-1271) days.

RESULTS

Of a total of 947 patients included, 735 (78%) had Rentrop 0 to 1 and 212 (22%) had Rentrop 2 to 3. During follow-up, 105 patients died, 71 from cardiovascular causes. In the matched cohort, the total mortality rate was similar between the 2 groups (Rentrop 0-1 [8.8%] vs Rentrop 2-3 [6.3%]; HR = 1.22; 95%CI, 0.50-2.94; P = .654). There were no differences in cardiovascular mortality (Rentrop 0-1 [4.6%] vs Rentrop 2-3 [2.3%]; sHR = 0.49; 95%CI, 0.14-1.62; P = .244) or the composite endpoint including cardiovascular death, reinfarction, target vessel revascularization, and coronary artery bypass surgery (Rentrop 0-1 [18.8%] vs Rentrop 2-3 [13.1%]; sHR = 0.68; 95%CI, 0.40-1.15; P = .157).

CONCLUSIONS

In this contemporary series, the presence of good CC before PA was not associated with better long-term clinical outcomes.

Comparison of Characteristics of Patients aged ≤45 Years Versus >45 Years With ST-Elevation Myocardial Infarction (from the AIDA STEMI CMR Substudy)

It is unknown whether the occurrence of ST-elevation myocardial infarction (STEMI) at a younger age is associated with differences in myocardial damage compared with older patients. We aimed to compare the infarct characteristics (area at risk [AAR], myocardial salvage index [MSI], infarct size [IS], microvascular obstruction [MVO]) and clinical outcome in patients aged ≤45 years and >45 years. We analyzed 795 patients with STEMI treated with primary percutaneous coronary intervention. All patients completed 12-month follow-up for the assessment of major adverse cardiac events (MACE). Left ventricular ejection fraction, AAR, MSI, IS, and MVO were determined by cardiac magnetic resonance imaging. Seventy-eight patients (9.8%) were aged 45 years or younger. Young patients were more likely to be male (p = 0.01), to be current smokers (p <0.001), and to have a family history of coronary artery disease (p = 0.05). Contrary, they had significantly lower prevalence of hypertension (p <0.001), diabetes (p <0.01), and 3-vessel disease (p <0.01). There were no significant differences in left ventricular ejection fraction (p = 0.36), AAR (p = 0.30), MSI (p = 0.34), IS (p = 0.29), or MVO (p = 0.58) between both groups. MACE rate was significantly lower in patients aged ≤45 years compared with patients aged >45 years (1.3% vs 7.5%, p = 0.04). After multivariate adjustment for clinical risk factors and cardiac magnetic resonance findings, age remained an independent predictor of MACE (hazard ratio 1.04, 95% CI 1.01 to 1.07, p = 0.03). In conclusion, infarct characteristics are not dependent on age in patients undergoing primary percutaneous coronary intervention for STEMI.

A protective role of early collateral blood flow in patients with ST-segment elevation myocardial infarction

Conflict persists regarding whether the presence of early collateral blood flow to the infarct-related artery has an effective role in reducing infarct size and improving myocardial salvage in patients with ST-segment elevation myocardial infarction (STEMI). We sought to investigate the impact of the collateral circulation on myocardial salvage and infarct size in STEMI patients.

METHODS

In 306 patients who were diagnosed with STEMI and underwent cardiac magnetic resonance within 1 week after revascularization, initial collateral flow to the infarct-related artery was assessed by coronary angiography. Using cardiac magnetic resonance imaging, myocardial infarct size and salvage were measured.

RESULTS

Among 247 patients with preprocedural Thrombolysis in Myocardial Infarction flow 0/1, 54 (22%) patients had good collaterals (Rentrop grade ≥ 2, Collateral Connection Score ≥ 2). Infarct size and area at risk were significantly smaller in patients with good collaterals than those with poor collaterals (infarct size: 17.1 ± 10.1 %LV vs 21.8 ± 10.5 %LV, P = .003, area at risk: 33.8 ± 16.8 %LV vs 38.8 ± 15.5 %LV, P = .039). There was a significant difference of myocardial salvage index between 2 groups (50.9% ± 15.0% vs 43.8% ± 18.5%, P = .005). Poor collateralization was an independent predictor for large infarct size (odd ratio 2.48 [1.28-4.80], P = .007).

CONCLUSIONS

In patients with STEMI, the presence of well-developed collaterals to occluded coronary artery from the noninfarct vessel and its extent were independently associated with reduced infarct burden and improved myocardial salvage. Our results help explain why MI patients with well-developed collateralization have reduced mortality and morbidity.

The impact of the coronary collateral circulation on outcomes in patients with acute coronary syndromes: results from the ACUITY trial

OBJECTIVE

We sought to assess the prognostic role of collaterals in a large population of patients presenting with an acute coronary syndrome (ACS).

METHODS

The coronary collateral circulation was assessed by an independent angiographic core laboratory using the Rentrop Score in patients enrolled in the randomised Acute Catheterization and Urgent Intervention Triage Strategy trial.

RESULTS

The cohort comprised 5412 patients with moderate to high risk ACS. A total of 858 patients (16.0%) had visible collaterals while 4554 patients (84.0%) had no collaterals. After multivariable adjustment, there were no differences in clinical outcomes at 1 year between the groups, including major adverse cardiac events (MACE) (HR 0.94 (95% CI 0.76 to 1.16), p=0.55), mortality (HR 1.03 (0.65 to 1.62), p=0.91), myocardial infarction (MI) (HR 1.07 (0.83 to 1.38), p=0.60) and unplanned target vessel revascularisation (TVR) (HR 0.95 (0.71 to 1.28), p=0.75). Similarly, in the subgroup of patients undergoing percutaneous coronary intervention (PCI), the adjusted HR for major adverse cardiac events was 1.1 (0.76 to 1.61), p=0.595; 0.81 (0.10 to 6.44), p=0.999 for mortality; and 0.86 (0.54 to 1.35), p=0.564 for MI. The risk of unplanned TVR was increased (HR 2.74 (1.48 to 5.10), p=0.004).

CONCLUSIONS

In contrast to other studies, this large core laboratory-based analysis does not confirm a beneficial role of visible coronary collateral vessels on clinical outcomes in patients with ACS; the presence of collaterals was even associated with increased mortality in the unadjusted analysis. Collaterals were associated with a higher risk of TVR in patients undergoing PCI, a finding that may not have been fully corrected given confounders and clinical differences between the groups.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00093158.

Effect of collaterals on deaths and re-infarctions in patients with coronary artery disease: a meta-analysis

BACKGROUND

It is generally believed that there is a beneficial effect of collaterals on death and re-infarction statistics in patients with coronary artery disease (CAD) but studies to date are small and inconsistent.

OBJECTIVE

To meta-analyse the studies published in this field in order to obtain more powerful information.

METHODS

We searched Medline and major journals (2000 to 2011) for studies evaluating the effect of coronary collaterals on mortality. Publication bias, lack of heterogeneity, and lack of robustness were assessed using the standard procedures for such purposes.

RESULTS

A total of 10 studies describing mortality, enrolling 6791 participants, were included in this analysis. In patients with collateralisation a significant relation with reduced mortality was seen compared with those without collateralisation, at an odds ratio of 0.47, p < 0.0001, and a reduction in deaths and re-infarctions at 0.54, p < 0.0001. Some publication bias, some heterogeneity and some lack of robustness were demonstrated. A meta-regression with the odds ratios of the presence of traditional atherosclerotic risk factors as predictors and the odds ratios of mortality and the composite deaths and re-infarctions as outcome showed no relationships.

CONCLUSIONS

In CAD patients from the post-percutaneous coronary intervention era the presence of collaterals reduced mortality by 0.47 (p < 0.0001) and deaths and re-infarctions by 0.54 (p < 0.0001). Furthermore, in the present meta-data, the atherosclerotic risk factors were no more present in patients with collaterals than they were in those without.

Effect of coronary collaterals on long-term prognosis in patients undergoing primary angioplasty for acute ST-elevation myocardial infarction

The aim of this study was to examine the effect of coronary collateral flow before reperfusion on long-term clinical prognosis in patients with acute ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention. We studied 235 patients with STEMI within 12 hours after symptom onset. All patients had Thrombolysis In Myocardial Infarction grade < or =1 flow before percutaneous coronary intervention. Collateral flow was graded according to the Rentrop classification. Patients were categorized as having absent or poor collateral flow to the infarct-related artery (group A) or significant flow (group B). In 166 patients there was absent or weak collateral flow (group A), whereas 69 had significant flow (group B). Long-term follow-up was available in 227 patients (97%) at a median of 797 days. Overall, 25 patients died during the follow-up period, 22 patients (13.8%) in group A and 3 patients (4.4%) in group B (p = 0.04). A total of 12 (7.5%) nonfatal recurrent myocardial infarctions occurred in group A compared to 2 (2.9%) in group B (p = 0.18). The combined major adverse cardiovascular event end point (death or nonfatal reinfarction) showed a significantly lower event rate in group B (p = 0.02). Extensive collateral flow at baseline was a significant predictor for a favorable long-term clinical outcome on multivariable analysis after adjustment for established prognostic markers. In conclusion, the presence of a well-developed collateral network before mechanical reperfusion in patients with STEMI is associated with improved long-term survival and lower major adverse cardiovascular event rates.