You-Hong Lee

The relationship between intravascular ultrasound-derived percent total atheroma volume and fractional flow reserve in the intermediate stenosis of proximal or middle left anterior descending coronary artery

BACKGROUND It remains undefined whether the atherosclerotic disease extent of the conductive vessel (expressed as intravascular ultrasound [IVUS]-derived percent total atheroma volume [%TAV]), correlates with functional severity of intermediate stenosis of left anterior descending artery (LAD). METHODS An IVUS study and fractional flow reserve (FFR) measurements performed in 130 patients with coronary angiographic intermediate stenosis of proximal or middle LAD. %TAV was calculated as the percentage of total vessel volume occupied by total atheroma volume on IVUS. RESULTS A significant correlation was observed between %TAV and FFR (r=-0.71, p<0.001). Minimal lumen area (MLA) correlated moderately with FFR (r=0.54, p<0.001). The independent predictors of FFR<0.8 were %TAV (odds ratio [OR]: 1.29, 95% confidence interval [CI]=1.18-1.40, p<0.001) and MLA (OR: 0.37, 95% CI=0.16-0.85, p=0.019). A receiver-operating characteristic curve suggested %TAV ≥ 39.0% (sensitivity 85%, specificity 83% and area under curve [AUC]=0.90) and MLA ≤ 2.6mm(2) (sensitivity 72%, specificity 70% and AUC=0.75) as the best cut-off values for FFR<0.8. Forty-eight point five (48.5%) of total studied lesions (63/130) showed %TAV ≥ 39.0%. Eighty-four point four (84.4%) of lesions (38/45) with %TAV ≥ 39.0% and MLA ≤ 2.6mm(2), and 72.2% of lesions (13/18) with %TAV ≥ 39.0% and MLA>2.6mm(2), FFR was less than 0.8. CONCLUSIONS Volumetric quantification of the atherosclerotic disease extent of the coronary artery, expressed as IVUS-derived %TAV, showed a strong correlation with FFR. Not only the segmental luminal narrowing but also the total plaque burden of conductive artery are major determinants for the presence of myocardial ischemia in intermediate stenosis of LAD.

β-Blocker Therapy in the Era of Primary Percutaneous Intervention for ST Elevation Myocardial Infarction

Objectives: With the present therapeutic advances in the era of primary percutaneous coronary intervention (PCI), the role of β-blockers in ST elevation acute myocardial infarction (STEMI) has remained contentious. Methods: We analyzed the data and clinical outcomes of 901 STEMI patients who had undergone primary PCI. We classified the patients into β-blocker (n = 598) and non-β-blocker groups (n = 303). Results: The cumulative incidence of all-cause death was 10.0% in the β-blocker group and 25.4% in the non-β-blocker group (p < 0.001). The incidence of major adverse cardiac events (MACE) was 22.1% in the β-blocker group and 34.3% in the non-β-blocker group (p < 0.001). The relative hazard ratio (HR) of β-blockers for all-cause death and MACE with low left ventricle ejection fraction (LVEF; <50%) was 0.55 [95% confidence interval (CI) 0.35-0.86, p = 0.009] and 0.75 (95% CI 0.51-1.09, p = 0.125), respectively. In patients with normal LVEF (≥50%), the relative HR of β-blockers for death and MACE were 0.50 (95% CI 0.29-0.88, p = 0.016) and 0.75 (95% CI 0.51-1.12, p = 0.162), respectively. After propensity score matching of the difference of the baseline characteristics, the Kaplan-Meier survival curve demonstrated lower mortality in the β-blocker group than in the non-β-blocker group with both low LVEF and normal LVEF (p = 0.02 and p = 0.001, respectively). Conclusions: β-Blockers have beneficial clinical outcomes in the era of primary PCI for STEMI, regardless of the LVEF.

Left ventricular hypertrophy on long-term cardiovascular outcomes in patients with ST-elevation myocardial infarction

Abstract Background: Left ventricular hypertrophy (LVH) had been associated with increased adverse cardiovascular events in hypertensive patients. Prognostic significance of LVH in patients with ST-elevation myocardial infarction (STEMI) is not established. This study aimed to investigate prognostic impact of LVH on the patients with STEMI. Methods: We analyzed the data and clinical outcomes of 30-day survivors with STEMI who underwent successful coronary intervention from 2003 to 2009. Definition of LVH was LV mass index (LVMI) >115 g/m2 in male and >95 g/m2 in female. Patients were classified into a LVH group and a non-LVH group. Occurrence of major adverse cardiovascular events (MACE; death, recurrent MI, target vessel revascularization (TVR)) within 5 years was evaluated. Results: We enrolled 418 patients and mean follow-up duration was 43 ± 17 months. Two hundred and fourteen patients (51%) had LVH. The survival of the patients with LVH was significantly worse than the patients without LVH (log-rank p = 0.024). In a multivariate regression model, the presence of LVH was independently associated with increased risk for all-cause mortality (OR, 2.37; 95% CI, 1.096–5.123, p = 0.028). When the end points were analyzed based on LVH severity, all-cause mortality was significantly correlated with LVH severity (p = 0.011). The severe LVH was independently associated with increased risk for all-cause mortality (OR, 5.110; 95% CI, 1.454–17.9, p = 0.001). Conclusion: LVH was associated with increased rate of adverse clinical outcomes in 30-day survivors after STEMI, who underwent successful coronary intervention.

Point-of-care measurements of platelet inhibition after clopidogrel loading in patients with acute coronary syndrome: comparison of generic and branded clopidogrel bisulfate.

PURPOSE Platelet-function suppression with antiplatelet therapy is effective in preventing and treating cardiovascular disease. Clopidogrel is a thienopyridine derivative that blocks platelet activation by adenosine diphosphate receptor binding. This study demonstrates the effects of generic clopidogrel bisulfate in comparison to branded clopidogrel bisulfate in patients with acute coronary syndromes. METHODS This prospective, 2-arm, single-center, open-label trial used 1:1 randomization to assign patients to receive generic or branded clopidogrel bisulfate. Patients with unstable angina or non-ST-segment elevation myocardial infarction and scheduled to undergo coronary angiography were enrolled. Platelet function was measured with a P2Y12 assay and reported in P2Y12 reaction units (PRU) and aspirin reaction units (ARU) after randomization. Platelet function was measured at 2, 4, 8, and 24 hours after 600-mg clopidogrel loading. The clinical outcome was checked at 1 month after coronary angiography. FINDINGS Ninety-five patients were enrolled and randomized to the generic or branded group. Ninety patients (62 men [69%], 28 women [31%]; mean age, 58 years) completed the study protocol. The clinical characteristics were similar between the 2 groups. The difference in the baseline PRU measurements between the generic and branded groups was not significant (274.8 [59.7] vs 285.4 [62.4], respectively; P = 0.414). There were significant differences in 2-hour PRU (231.1 [71.3] vs 266.9 [67.4]; P = 0.017) and 4-hour PRU (227.3 [80.4] vs 265.7 [71.0]; P = 0.020); however, 24-hour PRU (200.5 [82.1] vs 220.6 [75.8]; P = 0.253) was similar. No death, myocardial infarction, target lesion revascularization, stent thrombosis, or Thrombolysis in Myocardial Infarction-defined major bleeding complications were reported during in-hospital stay or 1-month follow-up. IMPLICATION In patients with ACS, loading of generic clopidogrel bisulfate was associated with an antiplatelet effect comparable to that of branded clopidogrel bisulfate. ClinicalTrials.gov identifier: NCT02060786.

Recurrent Stent Thrombosis in a Patient with Antiphospholipid Syndrome and Dual Anti-Platelet Therapy Non-Responsiveness

Antiphospholipid syndrome (APS), the most common acquired hypercoagulable condition, is diagnosed by persistent presence of antiphospholipid antibodies and episodes of vascular thrombosis. It may be an important predisposing factor for stent thrombosis, resulting in poor outcomes. Also, anti-platelet therapy non-responsiveness is associated with stent thrombosis. We report a case of a 39-year-old man who after undergoing successful percutaneous coronary intervention for significant coronary artery disease suffered repeated stent thrombosis events leading to ST-segment elevation myocardial infarction. Eventually, he underwent coronary artery bypass surgery because of uncontrolled thrombosis and was diagnosed as having APS and dual antiplatelet therapy non-responsiveness.