Albert Yuh-Jer Shen

Long-Term Outcomes by Clopidogrel Duration and Stent Type in a Diabetic Population With De Novo Coronary Artery Lesions

OBJECTIVES The purpose of this study was to determine whether long-term clinical outcomes differed between bare-metal stents (BMS) and drug-eluting stents (DES) by duration of clopidogrel use among diabetic patients. BACKGROUND There is concern that DES are associated with late adverse events such as death and myocardial infarction (MI) secondary to stent thrombosis. However, data on outcomes in diabetic patients remain limited. METHODS We identified 749 patients with diabetes mellitus who underwent stent implantation with either BMS (n = 251) or DES (n = 498) from October 2002 to December 2004. We performed survival analysis on the full cohort and on those event-free from death, MI, or repeat revascularization at 6 months (n = 671). RESULTS By clopidogrel duration, the event rate for death or MI was 3.2% in the >9-month group, 9.4% in the 6- to 9-month group, and 16.5% in the <6-month group, p < 0.001. For death alone, the event rate was 0.5% in the >9-month group, 4.3% in the 6- to 9-month group, and 10.0% in the <6-month group, p < 0.001. When taking BMS clopidogrel non-users as a referent in the multivariate analysis, the hazard ratio (95% confidence interval [CI]) for death and nonfatal MI for DES clopidogrel users, DES clopidogrel nonusers, and BMS clopidogrel users were: HR 0.22 (95% CI 0.08 to 0.62, p = 0.005), HR 0.39 (95% CI 0.13 to 1.13, p = 0.08), and HR 0.25 (95% CI 0.08 to 0.81, p = 0.02), respectively. CONCLUSIONS Longer duration of clopidogrel use was associated with a lower incidence of death or MI in both the BMS and DES groups. Among clopidogrel nonusers, the incidence of death/MI or death did not differ by stent type.

Racial/Ethnic differences in ischemic stroke rates and the efficacy of warfarin among patients with atrial fibrillation.

Background and Purpose— Warfarin reduces stroke risk in studies of predominantly white patients with atrial fibrillation (AF). Whether nonwhites also have lower rates of stroke while treated with warfarin is unclear. Methods— A multiethnic stroke-free cohort hospitalized with nonrheumatic AF was identified in a large health maintenance organization. Stroke risk factors (advanced age, diabetes, hypertension, and heart failure), warfarin use, and anticoagulation intensity were assessed. Crude ischemic stroke rates were calculated by Poisson regression for each group while using and not using warfarin. Cox proportional hazard models were constructed to assess the independent effect of race/ethnicity on ischemic stroke. Results— Between 1995 and 2000, we identified 18 867 AF hospitalizations (78.5% white, 8% black, 9.5% Hispanic, and 3.9% Asian). Over the course of 63 204 person-years follow-up (median, 3.3 years), 1226 ischemic strokes were identified. The percent-time on warfarin did not differ by race/ethnicity. The median percent-time on warfarin that international normalized ratio was 2 to 3 was 54.5% overall, but it was lower in blacks at 47.8%, whereas the other groups had a rate of ≈54%. The rate ratios (95% CI) of ischemic stroke with warfarin compared to without warfarin for whites, blacks, Hispanics, and Asians were 0.79 (0.68 to 0.90), 0.92 (0.65 to 1.30), 0.71 (0.48 to 1.05), and 0.65 (0.34 to 1.23), respectively. Conclusions— In this cohort, we did not observe a statistically significant lower rate of stroke with warfarin therapy among nonwhites (in particular blacks) with previous AF hospitalizations. The relatively small numbers of nonwhites renders our estimates less than precise and should be interpreted with caution.

Racial/Ethnic Differences in the Prevalence of Atrial Fibrillation Among Older Adults—A Cross-Sectional Study

BACKGROUND Atrial fibrillation affects 4% to 8% of individuals over 60 years of age based on studies of predominantly white populations, whether this is true among nonwhite individuals is not clear. This study was undertaken to define racial/ethnic differences in atrial fibrillation prevalence among a large community cohort. METHODS This is a cross-sectional study. In 2008, there were 430,317 members aged 60 years or older in a large California health maintenance organization. By searching International Classification of Diseases, Ninth Revision codes and electronic electrocardiographic archives, we identified all members in this age group with primary, nonvalvular atrial fibrillation. Race/ethnicity data were assigned using health plan enrollment, service utilization, Asian/Hispanic surname and geocoding methods, and was available for 80.5% of members (79.8% of non-atrial fibrillation and 92% of atrial fibrillation), 99% of which were white, black, Asian, or Hispanic. We assessed the age- and gender-specific atrial fibrillation prevalence rates for each racial/ethnic group. The effect of race/ethnicity on atrial fibrillation was analyzed with logistic regression methods adjusting for potential confounders. RESULTS The overall atrial fibrillation prevalence was 5.3%. Among members with assigned race/ethnicity data, the prevalence among whites, blacks, Asians, and Hispanics was 8.0%, 3.8%, 3.9%, and 3.6%, respectively. The adjusted odds ratios (95% confidence intervals) of atrial fibrillation among blacks, Asians, and Hispanics with whites as referent were 0.49 (0.47-0.52), 0.68 (0.64-0.72), and 0.58 (0.55-0.61), respectively. CONCLUSIONS Atrial fibrillation is less prevalent in older nonwhite individuals than whites. White race/ethnicity is associated with significantly greater odds for atrial fibrillation compared to blacks, Asians, and Hispanics, after adjusting for comorbidities associated with the development of atrial fibrillation.

Effect of Race/Ethnicity on the Efficacy of Warfarin : Potential Implications for Prevention of Stroke in Patients with Atrial Fibrillation

Atrial fibrillation (AF) is the most common sustained arrhythmia seen in clinical practice. It affects approximately 6% of persons over 65 years of age and is independently associated with a 4-to 5-fold higher risk of ischaemic stroke and a 2-fold higher risk of death. Randomized controlled trials have shown that treatment with adjusted-dose oral vitamin K antagonists (primarily warfarin with a target international normalized ratio [INR] of 2.0–3.0) reduces the relative risk of ischaemic stroke by two-thirds (an approximately 3% reduction in annual absolute risk), but is associated with a 0.2% excess annual absolute risk of intracranial haemorrhage (ICH). However, in ‘real world’ studies, the risk reductions in ischaemic stroke with warfarin have been significantly lower (25–50% relative risk reduction) than in selected trial samples. Moreover, more than 90% of patients enrolled in the sentinel trials were White/European. This raises the question of whether the beneficial results of warfarin can be extrapolated to persons of colour. Important differences in stroke risk profile and responsiveness to warfarin exist across racial/ethnic groups, such that one cannot assume a priori that there is a net benefit of warfarin therapy for AF patients of all racial/ethnic groups.Among patients with ischaemic stroke, AF is more likely to be implicated as the cause of stroke in the White population than in other racial/ethnic groups. Furthermore, AF may be a stronger predictor of ischaemic stroke among the White population than in Black or Hispanic/Latino populations. Approximately one-third of strokes in AF patients are noncardioembolic. Warfarin has been shown to be ineffective in preventing recurrent noncardioembolic strokes. Many persons of colour with AF have other risk factors that predispose them to noncardioembolic stroke, which may partially explain why warfarin has been reported to be less efficacious in preventing strokes in non-White patients with AF, even after adjustment for co-morbidities and anticoagulation monitoring. Notably, the background incidence of ICH is higher in Black, Hispanic and Asian patients than in White patients. Any greater than expected increases in bleeding secondary to anticoagulation may potentially offset any benefit gained from cardioembolic stroke reduction, although this has not been fully resolved.Finally, there are racial/ethnic differences in the prevalence of certain polymorphisms in genes that influence warfarin pharmacokinetics and pharmaco-dynamics (e.g. cytochrome P450 2C9 and vitamin K epoxide reductase). The Asian population generally appear to require the lowest daily dose of warfarin to maintain a given INR target, with the White population requiring an intermediate daily dose and the Black population requiring the highest daily dose. These differences must be taken into account when administering warfarin in order to minimize the risk of under-or over-anticoagulation.In summary, warfarin is highly effective in preventing ischaemic strokes in White patients with AF at a modestly higher risk of ICH. Whether the same net clinical benefit extends to persons of colour is unproven. Given the rapidly changing demographic nationally and internationally, additional research is needed to resolve this important question.

Discontinuation of Long-Term Clopidogrel Therapy Is Associated With Death and Myocardial Infarction After Saphenous Vein Graft Percutaneous Coronary Intervention

OBJECTIVES This study sought to examine the pattern of death and myocardial infarction (MI) after clopidogrel cessation in patients undergoing percutaneous coronary intervention (PCI) of the saphenous vein graft (SVG). BACKGROUND The timing and incidence of adverse events by different durations of clopidogrel therapy after SVG PCI remain unknown. METHODS This is a cohort study of patients undergoing SVG PCI between 2000 and 2009, followed for all-cause mortality or MI after stopping clopidogrel. Incidence rates were calculated across different time periods after clopidogrel cessation. Adjusted incidence rate ratios (IRR) were calculated with multivariable regression (piecewise exponential and Poisson). RESULTS There were 603 patients who underwent SVG PCI, of which 411 were event-free at the time of clopidogrel cessation. The incidence rate (95% confidence interval: [CI])/1,000 person-days of death or MI after stopping clopidogrel in the time intervals of 0 to 90 days, 91 to 365 days, and 1 to 2 years were 1.26 (95% CI: 0.93 to 1.70), 0.41 (95% CI: 0.30 to 0.56), and 0.41 (95% CI: 0.30 to 0.55), respectively. In multivariable analyses, the overall IRR (95% CI) for death or MI in the 0- to 90-day interval after stopping clopidogrel compared with the 91- to 365-day interval was 2.58 (95% CI: 1.64 to 4.07). Similar results were observed over a broad range of clopidogrel treatment durations (<6 months, 6 months to 1 year, 1 to 2 years, or >2 years). The results were also consistent across subgroups, including sex, stent type, stent diameter, PCI period, and diabetes status. When death alone was evaluated, there remained a significant increase in the event rate in the 0- to 90-day interval compared with the 91- to 365-day interval (IRR: 2.33; 95% CI: 1.32 to 4.11). CONCLUSIONS A clustering of events was observed in the initial 0 to 90 days after clopidogrel cessation in all treatment durations of clopidogrel investigated after SVG PCI. These results might have important implications in high-risk cohorts undergoing PCI. Additional studies are needed to elucidate the mechanisms underlying the early clustering of events after clopidogrel cessation.

Primary angioplasty for acute myocardial infarction resulting from the simultaneous occlusion of two major coronary arteries

Primary angioplasty for acute myocardial infarction is frequently performed. Not uncommonly, more than one occluded artery may be present. Usually only one is an acute event, the others being chronic occlusions. We encountered a patient who presented with two simultaneous occlusions; both were successfully recanalized. We discuss some observations that assisted us in devising our treatment strategy. Cathet. Cardiovasc. Intervent. 47:203–207, 1999.

Is pregnancy contraindicated after cardiac transplantation? A case report and literature review

We report a cardiac allograft recipient who conceived 5 months after transplantation and spontaneously delivered a full term healthy baby girl. Pregnancy in cardiac transplant recipients is gradually becoming a more frequent issue as more patients in this population consider child bearing. In order to advise patients on potential adverse outcomes due to pregnancy, we reviewed the literature on pregnancy after cardiac transplantation. Published reports show that pregnancy in this population carry a higher risk for complications, in particular there is a higher incidence of pregnancy-induced hypertension, preeclampsia, premature labor, premature and low birth weight infants. The risk for these complications, however, is not higher than for pregnancies of renal or liver transplant recipients, to which pregnancy is not invariably advised against. Despite a greater frequency of complications during pregnancy, successful delivery of a healthy infant is the rule, without any detectable long-lasting adverse effects on both mother and offspring. Thus, while cardiac transplant recipients who wish to become pregnant should be counseled on possible complications, it appears that a satisfactory outcome can generally be expected. Additionally, we discuss further issues pertinent to the care of such patients, including hemodynamic changes, immunosuppression, and rejection surveillance during their pregnancies.

Statin use prior to angiography for the prevention of contrast-induced acute kidney injury: a meta-analysis of 19 randomised trials.

AIMS A systematic review and a meta-analysis were performed to define better the role of statin use prior to angiography in preventing contrast-induced acute kidney injury (CI-AKI). METHODS AND RESULTS MEDLINE, Embase, Cochrane Library, references from review articles, and conference proceedings were searched, with no language restriction, for randomised controlled trials (RCT) evaluating the use of statin therapy prior to angiography for the prevention of CI-AKI. Nineteen RCTs including 7,161 patients were identified. The pooled analysis demonstrated a significant reduction in the incidence of CI-AKI in patients treated with statin prior to invasive angiography when compared with control (RR 0.52; 95% CI: 0.40-0.67). Patients with chronic kidney disease stage 3 or worse were largely underrepresented in these trials, and statin therapy did not significantly reduce the risk of CI-AKI in the three studies which enrolled a patient population with a mean eGFR of <60 ml/min (RR 0.54; 95% CI: 0.2-1.42). CONCLUSIONS This meta-analysis suggests a potential benefit for statin use prior to angiography to reduce the incidence of CI-AKI. Additional research is needed to define better the benefits of statin therapy prior to angiography to prevent CI-AKI, especially in high-risk patients with chronic kidney disease who were largely underrepresented in the available trials.

Predictors of Survival After Coronary Bypass Grafting in Patients With Total Occlusion of the Left Main Coronary Artery

Twenty-three patients with angiographically documented total occlusion of the left main coronary artery were retrospectively identified. Statistical analysis suggests that poor right-to-left collaterals and the presence of concurrent significant right coronary artery disease were weakly associated with decreased survival after bypass surgery.

Atrial Fibrillation and Atrial Flutter in Pregnant Women—A Population‐Based Study

Background The goal of this study was to determine the prevalence of atrial fibrillation and atrial flutter (AF) in pregnant women and to examine the impact of AF on maternal and fetal outcomes. Methods and Results Between January 1, 2003 and December 31, 2013, there were 264 730 qualifying pregnancies (in 210 356 women) in the Kaiser Permanente Southern California hospitals, among whom AF was noted in 157 pregnancies (129 women; 61.3 per 100 000 women, or 59.3 per 100 000 pregnancies). Prevalence of AF (per 100 000 women) in white, black, Asian, and Hispanic women was 111.6, 101.7, 45.0, and 34.3, respectively. Older age was associated with higher odds of having AF. Compared to women <25 years of age, the odds ratio (OR) of AF was 4.1 in women age 30 to 34 years, 4.9 in women age 35 to 39 years, and 5.2 in women age ≥40. Odds of AF episodes were higher during the third trimester compared to the first trimester (OR, 3.2; 95% CI: 1.5–7.7). Among AF patients, adverse maternal cardiac events were rare—2 women developed heart failure and there were no strokes or systemic embolic events and no maternal death. There were 156 live births (99.4% of all pregnancies). Compared to women without AF, fetal birth weights were similar, but rate for neonates’ admission to the neonatal intensive care unit was higher (10.8% vs 5.1%; P=0.003). Conclusions AF is rare in pregnant women. Certain factors such as increased maternal age and white race increase the odds of having AF. Major maternal and fetal complications are infrequent, albeit a source of concern.