Acute myocardial infarction in young Asian women: a comparative study on Chinese, Malay and Indian ethnic groups

INTRODUCTION

There is a paucity of data on acute myocardial infarction (AMI) in young Asian women and of comparative data among various ethnic groups with respect to risk factor profile and clinical outcomes. We present a comprehensive overview of the clinical characteristics of young Asian women with AMI and a comparative analysis among Chinese, Malay and Indian women in a multi-ethnic Asian country.

METHODS

We studied 45 Asian female patients aged 50 years and below who were admitted to our hospital with a diagnosis of ST-segment elevation myocardial infarction (STEMI) or non-ST-segment elevation myocardial infarction (NSTEMI).

RESULTS

Overall, diabetes mellitus, hypertension and hyperlipidaemia were prevalent in the study population. Hyperlipidaemia was more prevalent among Indian patients, while diabetes mellitus was more common among Malay patients. Only a minority of the study patients were current smokers. Among the 20 patients admitted with STEMI, 17 (85 percent) received urgent reperfusion therapy. The mean symptom-to-balloon time and door-to-balloon time for the Malay patients were longer compared to those for other ethnic groups. Among the 25 patients admitted with NSTEMI, 12 (48 percent) underwent coronary revascularisation therapy. The average duration of hospital stay was 4 +/- 4.1 days, with no significant difference observed among the various ethnic groups.

CONCLUSION

Many young Asian women with AMI have identifiable risk factors that are different from those found in the Western population. There seems to be an ethnic effect on the prevalence of these risk factors and door-to-balloon time.

Prevalence and predictors of premature discontinuation of dual antiplatelet therapy after drug-eluting stent implantation: importance of social factors in Asian patients

AIM

Premature discontinuation of antiplatelet therapy is an independent predictor of late stent thrombosis. We sought to determine the prevalence and predictors of premature discontinuation of antiplatelet therapy after drug-eluting stent implantation among patients in Asia.

METHODS

A total of 207 consecutive patients who underwent drug-eluting stent implantation at our institution was followed up after 1 year. Premature discontinuation of antiplatelet therapy was defined as omission of aspirin and/or clopidogrel for 1 week or more.

RESULTS

Four (1.9%) patients died and the remaining 203 patients formed the study population. Prevalence of premature discontinuation of antiplatelet therapy was 12.8% (n= 26, aspirin, n= 12; clopidogrel, n= 9; both, n= 5). The median duration between stent implantation and discontinuation of antiplatelet therapy was 2.8 months. Reasons for discontinuation included cost (n= 1), gastric discomfort (n= 1), allergy (n= 3), bleeding (n= 3), advice from doctors (n= 7) and no reason (n= 11). Logistic regression showed that living alone was the only independent predictor of premature discontinuation of dual antiplatelet therapy (50.0% vs 11.3%, P= 0.001).

CONCLUSION

Among Asian patients who have undergone drug-eluting stent implantation, 12.8% discontinued dual antiplatelet therapy within 12 months. Living alone is associated with a fivefold increase in risk of premature drug discontinuation.

High-sensitivity C-reactive protein is predictive of medium-term cardiac outcome in high-risk Asian patients presenting with chest pain syndrome without myocardial infarction

INTRODUCTION

High-sensitivity C-reactive protein (hs-CRP) has been shown to be predictive of cardiac events but data among Asians is comparatively few. We evaluated the role of hs-CRP in the prediction of adverse cardiac outcome in a cohort of high-risk patients presenting with chest pain syndrome without myocardial infarction (MI).

MATERIALS AND METHODS

Three hundred and forty-seven patients were prospectively recruited over an 18-month period and patients with MI as documented by serial electrocardiogram abnormalities, and creatinine kinase or troponin elevation were excluded. Mean follow-up duration was 901 +/- 306 days. Kaplan-Meier and Cox proportional hazards modelling were used to evaluate outcome and determine association with predictor variables.

RESULTS

The composite primary endpoint of cardiac mortality, non-fatal MI, cardiac failure or coronary revascularisation procedure (coronary artery bypass grafting or angioplasty) unrelated to the index admission was reached in 37 patients. History of previous MI (P = 0.002), presence of at least 1 coronary artery with > or =50% stenosis (P = 0.028) and elevated hs-CRP levels were associated with an adverse cardiac outcome (P = 0.001 for CRP in the upper quartile, and 0.002 for CRP > or = 1mg/L, respectively). None of the traditional cardiovascular risk factors (hypertension, diabetes mellitus, dyslipidaemia, significant family history, smoking, male gender and increased age) was predictive. Multivariate modelling showed elevated hs-CRP to confer the highest risk for an adverse cardiac outcome (P <0.001).

CONCLUSION

Hs-CRP is useful in further stratifying high-risk multi-ethnic patients presenting with chest pain despite no evidence of MI. Close follow-up and aggressive management of these patients may be warranted.

The impact of diabetes mellitus on the prognostic value of a normal dobutamine stress echocardiogram in patients with intermediate to high cardiovascular risk

INTRODUCTION

There is currently limited data on the prognostic value of a normal dobutamine stress echocardiogram (DSE) in patients with intermediate to high cardiovascular risk. The impact of diabetes mellitus, recently recognised as a cardiovascular risk-equivalent, has not been previously evaluated. This study aims to determine the prognostic value of a normal DSE in these patients.

METHODS

The study population includes all patients with two cardiovascular risk factors or diabetes mellitus and a normal DSE (baseline and peak stress) with three months follow-up. A total of 122 patients (47 females, 75 males; mean age 59.6 years) were recruited. Impact of diabetes mellitus on subsequent cardiovascular events was determined.

RESULTS

Diabetes mellitus was present in 32.8 percent, hypertension in 72.1 percent, smoking in 27.0 percent, family history of premature coronary artery disease in 15.6 percent, and hypercholesterolemia in 66.4 percent. On follow-up until 6.4 years (mean 4.1 years), there were four myocardial infarctions (0.8 percent per patient/year) and five revascularisation procedures (1.0 percent per patient/year). The majority of adverse events occurred among patients with diabetes mellitus (three out of four myocardial infarctions; four out of five revascularisations). Diabetes mellitus independently predicted subsequent cardiac events on both univariate and multivariate analyses (p value is equal to 0.015 and 0.011, respectively). Presence of diabetes mellitus also conferred a worse outcome on survival analysis (p value is equivalent to 0.0046).

CONCLUSION

The presence of diabetes mellitus adversely affects clinical outcome despite a normal DSE. Patients without diabetes mellitus, but with intermediate to high cardiovascular risk, and a normal DSE have a better medium term outcome.