Kyoung-Woo Seo

Recurrence of left ventricular dysfunction in patients with restored idiopathic dilated cardiomyopathy.

In some patients with nonischemic idiopathic dilated cardiomyopathy (DCM), left ventricular (LV) dysfunction improves spontaneously but can recur. The factors predicting recurrence of LV dysfunction in recovered idiopathic DCM are poorly defined. We investigated the clinical, echocardiographic, and laboratory variables affecting recurrence of LV dysfunction in patients who recovered from DCM.

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.

Usefulness of Hyperemic Microvascular Resistance Index as a Predictor of Clinical Outcomes in Patients with ST-Segment Elevation Myocardial Infarction

Background and Objectives Microvascular function is a useful predictor of left ventricular functional changes in patients with ST-segment elevation myocardial infarction (STEMI). We evaluated the usefulness of the hyperemic microvascular resistance index (hMVRI) for predicting long-term major adverse cardiovascular events (MACEs) in patients with STEMI assessed immediately after primary percutaneous coronary intervention (PCI). Subjects and Methods hMVRI were evaluated in 145 patients with first acute STEMI treated with primary PCI using an intracoronary Doppler wire. hMVRI was defined as the ratio of mean aortic pressure over hyperemic averaged peak velocity of infarct-related artery. Major adverse cardiovascular events (MACEs) included cardiac death and re-hospitalization for congestive heart failure. Results During the mean follow-up of 85±43 months, MACEs occurred in 17.2% of patients. Using a receiver-operating characteristics analysis, hMVRI >2.82 mm Hg·cm-1·sec (sensitivity: 87%; specificity: 69%; and area under curve: 0.818) was the best cut-off values for predicting future cardiac events. The Cox proportional hazard analysis showed that hMVRI was an independent predictor for long-term MACEs (hazard ratio 1.741, 95% confidence interval 1.348-2.264, p<0.001). The Kaplan-Meier survival analysis showed a higher incidence of MACEs in patients with hMVRI >2.82 mm Hg·cm-1·sec (p<0.001). Conclusion hMVRI was a strong predictor of long-term MACEs in patients with STEMI treated with primary PCI.

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.

Impact of Changes in Myocardial Velocity Assessed by Tissue Doppler Imaging during Exercise on Dynamic Mitral Regurgitation in Patients with Nonischemic Cardiomyopathy

Background: We evaluated the myocardial contractile reserve related to exercise‐induced changes in functional mitral regurgitation (MR) by tissue Doppler imaging (TDI). Methods: Supine bicycle exercise was performed in 35 patients with nonischemic cardiomyopathy (age 51 ± 12 years; EF < 40%) and resting, and peak exercise 2D echocardiographic parameters, and TDI data were obtained. Vavg was defined as the average of peak systolic velocities of six basal LV segments by TDI. Myocardial contractile reserve, which was calculated by [peak exercise Vavg– baseline Vavg], was represented as ΔVavg. Dyssynchrony index was derived from the standard deviation of the time to the peak systolic velocity of 12 LV segments. Results: During exercise (9.7 ± 2.4 minutes), the mean Vavg increased from 4.0 ± 0.8 cm/s to 5.5 ± 1.0 cm/s. The effective regurgitant orifice area (ERO) and the ratio of MR jet area to the left atrial area (JLA%) were 1.9 ± 2.9 mm2 and 12 ± 12%, respectively. During exercise, ERO and JLA% significantly increased to 6.2 ± 6.4 mm2 and 21 ± 13% (P < 0.05), respectively, with individually variable changes. Tenting area was found to be an independent factor that showed a relationship with the baseline severity of MR (r = 0.561, P < 0.001). Dyssynchrony index and ΔVavg were found to correlate with both maximal MR severity at peak exercise and changes in MR during exercise. By multivariate analysis, ΔVavg was found to be an independent determinant of exercise‐induced changes in ERO (ΔERO; r =−0.707, P< 0.001) and changes in JLA% (ΔJLA%; r =−0.663, P< 0.001). Conclusion: In patients with nonischemic cardiomyopathy, impaired contractile reserve assessed by TDI velocity data may be an independent determinant affecting exercise‐induced changes in dynamic MR.

Ischemia-based Coronary Revascularization: Beyond Anatomy and Fractional Flow Reserve

Treatment strategies for patients with coronary artery disease (CAD) should be based on objective evidence of inducible ischemia in the subtended myocardium to improve clinical outcomes, symptoms, and cost-effectiveness. Fractional flow reserve (FFR) is the most verified index to-date for invasively evaluating lesion-specific myocardial ischemia. Favorable results from large clinical trials that applied FFR-guided percutaneous coronary intervention (PCI) prompted changes in coronary revascularization guidelines to emphasize the importance of this ischemia-based strategy using invasive coronary physiology. However, the frequency of functional evaluations is lacking in daily practice, and visual assessment still dominates treatment decisions in CAD patients. Despite recent efforts to integrate functional and anatomical assessments for coronary stenosis, there is considerable discordance between the 2 modalities, and the diagnostic accuracy of simple parameters obtained from current imaging tools is not satisfactory to determine functional significance. Although evidence that supports or justifies anatomy-guided PCI is more limited, and FFR-guided PCI is currently recommended, it is important to be aware of conditions and factors that influence FFR for accurate interpretation and application. In this article, we review the limitations of the current anatomy-derived evaluation of the functional significance of coronary stenosis, detail considerations for the clinical utility of FFR, and discuss the importance of an integrated physiologic approach to determine treatment strategies for CAD patients.

Impact of body fat distribution on long-term clinical outcomes after drug-eluting stent implantation

Background and objective The distribution of body fat is closely related to cardiovascular disease and outcomes, although its impact on patient prognosis after percutaneous coronary intervention (PCI) with drug-eluting stent (DES) has not been evaluated. We investigated the impact of truncal fat distribution on long-term clinical outcomes after DES treatment. Methods In 441 DES-treated patients, dual energy X-ray absorptiometry was performed to assess total and regional body fat distribution after index PCI. The ratio of truncal fat to total body fat mass (%FMtrunk/FMtotal) was calculated as a representative parameter for truncal fat distribution. The primary endpoint was major adverse cardiac events (MACE), a composite of ischemia-driven target vessel revascularization (TVR), non-procedural myocardial infarction, cardiac death at 5 years. Results During the median follow-up duration of 1780 days, MACE occurred in 22.0% of patients, with the highest-quartile group of %FMtrunk/FMtotal having a higher rate than the lowest quartile group (27.8% vs. 15.3%; log rank p = 0.026). The difference was driven by a higher rate of ischemia-driven TVR (25.9% vs. 9.9%; log rank p = 0.008). In multivariable Cox regression analyses, %FMtrunk/FMtotal was independently associated with MACE (hazard ratio: 1.075; 95% CI: 1.022–1.131; p = 0.005), but body mass index (BMI) was not. Conclusions In DES-treated patients, truncal fat distribution is associated with unfavorable clinical outcomes and is more clinically relevant than BMI.

Calcified Cardiac Mass Compressing Coronary Artery

Cardiac multidetector computed tomography (MDCT) showed 6.4 cm × 2.8 cm × 3.2 cm‐sized calcified mass in the left ventricular (LV) myocardium involving basal to midlateral segments [Figure 1a‐1c]. A huge, heavily calcified mass was entirely occupied within the myocardium of the lateral segments of LV. Small daughter mass was located within the interventricular septum, extending to anterior‐free wall of LV septum. Small mass seemed to compress the left anterior descending artery (LAD). Echocardiography revealed hyperechoic mass involving basal to mid‐lateral LV segments [Figure 1d]. Coronary angiography was performed and revealed total occlusion of LAD due to small Calcified Cardiac Mass Compressing Coronary Artery