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.

Invasive assessment of coronary flow reserve impairment in severe aortic stenosis and ecochadiographic correlations.

OBJECTIVES AND BACKGROUND: Patients with aortic stenosis (AS) may have impaired coronary flow reserve (CFR) despite angiographically normal coronary arteries. This is the first report of invasive thermodilution-derived CFR and IMR in patients with AS and their associations with echocardiographic parameters for AS assessment. METHODS: Thirty-six consecutive severe AS patients and ten patients without AS underwent prospectively cardiac catheterization and coronary physiological parameters were determined in the left anterior descending (LAD). Mean transit time (Tmn), a surrogate of absolute coronary flow, was obtained from the coronary thermodilution curve. RESULTS: In AS patients we found a high LAD flow at rest (Tmn rest 0.55±0.3 vs 0.99±0.4, p=0.01) and a low flow at hyperemia (Tmnhyp 0.44±0.2 vs 27.7±0.1, p=0.02) and consequently a severe CFR impairment (1.4±0.4 vs 3.8±1.4, p<0.001) compared with controls. An elevated index of microvascular resistance (IMR) (32.7±16 vs 17.8±6.5, p=0.01) and a low baseline microvascular coronary resistance (48.1±29 vs 84±34, p=0.02) were also found. In AS patients there were significant correlations between CFR and left ventricular mass index (r=-0.32; p=0.02), and the ratio of acceleration time to ejection time (AT/ET) (r=-0.4; p=0.01) a non-flow dependent echocardiographic parameter for AS assessment. Multiple linear stepwise regression analysis showed that AT/ET (ß=-0.441, p=0.019) was the only independently variable associated with CFR CONCLUSIONS: In severe AS, invasive CFR shows a progressive decrease with AS severity and a good correlation with echocardiographic parameters of AS, especially with flow-independent ones.