Protective effect of pre-infarction angina on microvascular obstruction after primary percutaneous coronary intervention is blunted in humans by cardiovascular risk factors.

BACKGROUND: Pre-infarction angina (PIA) has been shown to reduce the microvascular obstruction (MVO) rate in patients with ST-segment elevation myocardial infarction (STEMI). We sought to evaluate the potential modulator role of cardiovascular risk factors (CRFs) on this protective effect. METHODS AND RESULTS: Two hundred patients with STEMI were enrolled. PIA was defined as typical chest pain within the 48 h preceding STEMI onset. Angiographic MVO was defined as TIMI flow grade <2 or TIMI flow 3 with myocardial blush grade <2; electrocardiographic (ECG) MVO was defined as ST-segment elevation resolution <70%. Common CRFs were collected. In the absence of hypertension, both angiographic and ECG MVO rates were lower in patients with PIA as compared with those without, whereas, in the presence of hypertension, they were similar in both study groups (P for interaction=0.01 and P=0.014, respectively). Among nonsmokers, angiographic and ECG MVO rates were lower in patients with PIA as compared with those without, whereas within smokers, they were similar in both study groups (P for interaction=0.037 and P=0.037, respectively). In the absence of dyslipidemia, the angiographic and ECG MVO rates were lower in patients with PIA as compared with those without, whereas within dyslipidemic patients, they were similar in both study groups (P for interaction=0.012 and P=0.04, respectively). CONCLUSIONS: The protective effect of PIA on MVO is blunted by CRFs.

Impact of accuracy of fractional flow reserve to reduction of microvascular resistance after intracoronary adenosine in patients with angina pectoris or non-ST-segment elevation myocardial infarction.

Our study aimed to elucidate mechanisms underlying discordance between fractional flow reserve (FFR) and hyperemic stenosis resistance (hSR) in some patient subsets. To do this, we enrolled 30 consecutive patients with stable angina or non-ST elevation myocardial infarction (non-STEMI) and with a nonculprit intermediate coronary lesion (40% to 70%) by coronary angiography. We measured aortic pressure, flow velocity, and pressure distal to lesion simultaneously at basal level and during adenosine-induced (fixed intracoronary dose of 120 µg) hyperemia using a dual-sensor-equipped guidewire. Microvascular resistance (MR; pressure distal to lesion/flow velocity, mm Hg/cm/s) and variation (Δ) in MR levels were calculated both at baseline and after hyperemia, whereas FFR (cutoff <0.80) and hSR [(aortic pressure - pressure distal to lesion)/flow velocity, cutoff >0.80 mm Hg/cm/s] were assessed after intracoronary adenosine. Twenty-three patients (76.7%) showed concordance and 7 patients (23.3%) showed discordance between FFR and hSR (all cases with FFR >0.80 and hSR >0.80). Discordant patients presented more frequently with non-STEMI (85.7% vs 39.1%, p = 0.04), significantly higher C-reactive protein serum levels (median [interquartile range] 5.9 [5.1 to 6.8] vs 4.9 [3.7 to 6.2] mg/L, p = 0.007), and lower ΔMR (p = 0.03) values compared with concordant patients. In conclusion, patients with non-STEMI and those with increased C-reactive protein levels show a lower reduction in MR after intracoronary adenosine-induced hyperemia, leading to FFR underestimation.

Effect of low doses of alcohol on the warm-up phenomenon in patients with stable angina pectoris.

Experimental studies suggest that alcohol may have protective effects similar to that of ischemic preconditioning (IPC). The acute effects of alcohol on IPC in humans, however, are poorly known. In this study, we assessed the effect of alcohol administration on the warm-up phenomenon, as an expression of IPC, in patients with stable coronary artery disease (CAD). We randomized 45 stable CAD patients with positive (ST-segment depression > or =1 mm) exercise stress test to 1 of 3 groups of 15 patients each: (1) group 1 = 60 cc of gin (18.5 g of ethanol); (2) group 2 = 180 cc of red wine (18.9 g of ethanol); and (3) group 3 = placebo (120 cc of water). A first exercise test was performed 15 minutes after beverage administration. In those with a positive exercise test (13, 14, and 14 patients in the gin, wine, and placebo groups, respectively), a second exercise test was performed 15 minutes after the end of the first one. On the first test, there were no differences among groups in rate pressure product and time of exercise at 1-mm ST-segment depression, as well as in maximal ST segment depression. Furthermore, an improvement of the ischemic exercise variables was observed in each group, without any statistically significant differences among them. In conclusion, our data show that, in stable CAD patients, the acute intake of low doses of alcohol does not significantly influence IPC, as expressed by the warm-up phenomenon on exercise stress testing.

Ethanol abolishes ischemic preconditioning in humans.

OBJECTIVES: This study sought to assess the effect of acute alcohol intake on ischemic preconditioning (IPC) in humans using the clinical model of 2 sequential balloon inflations during a percutaneous coronary intervention (PCI). BACKGROUND: Ischemic preconditioning is the most potent form of endogenous myocardial protection from irreversible ischemic injury. Experimental observations suggest that acute ethanol administration might abolish IPC. METHODS: We studied 30 consecutive patients (22 men, mean age 65 years) undergoing elective coronary angioplasty who were randomized to receive an oral dose of 40 g ethylic alcohol (administered as 149 ml of Gordon's Gin) or 149 ml of water 30 min before PCI. Intracoronary electrocardiogram was continuously monitored to assess the greatest ST-segment elevation or depression from baseline. RESULTS: In placebo-treated patients, the change of ST-segment shift during the second inflation was significantly smaller than that during the first inflation (19.3 +/- 9.1 vs. 15.7 +/- 8.7, p = 0.005). In contrast, in gin-treated patients, the change of ST-segment shift during the second inflation was significantly greater than that during the first inflation (18.7 +/- 7.2 vs. 22 +/- 10, p = 0.03). The group-inflation interaction for ST-segment changes was highly significant (p < 0.001). CONCLUSIONS: This randomized, prospective study in humans shows that administration of a moderate dose of ethanol abolishes IPC occurring during sequential episodes of myocardial ischemia and is associated with worsening ischemia. Based on our study, intake of moderate to high doses of alcoholic beverages should be avoided in patients at high risk of acute myocardial infarction.

[Association between ethanol intake and ischemic heart disease]. / Rapporti tra etanolo e cardiopatia ischemica.

Most world populations consume alcoholic beverages. Ethanol may have both protective and harmful effects on health depending on the amount and way of consumption. An extensive body of data shows concordant J or U-shaped associations between alcohol intake and a variety of adverse health outcomes, including coronary heart disease, diabetes, hypertension, congestive heart failure, stroke, and all-cause mortality. In particular, moderate ethanol consumption is associated with cardioprotective benefits such as lower cardiovascular risk and mortality, probably mediated by beneficial effects on inflammation, lipids, and coagulation. In contrast, binge and/or heavy drinking results in proportional worsening of outcomes, increasing cardiovascular events and mortality. This harmful effect has been recently associated with the blockade of ischemic preconditioning mediated by high doses of ethanol. In this review, we highlight the recent epidemiological and experimental evidences regarding the specific benefits and risks of ethanol in the setting of ischemic heart disease.