OBJECTIVE: To determine (i) proportions of patients with CHD in Singapore who achieved goals for serum low-density lipoprotein-cholesterol (LDL-C); and (ii) factors influencing goal attainment.
METHODS: A historical cohort study was conducted using records from the Singapore Cardiac Databank, a national registry of CHD patients. Serum LDL-C goal attainment was assessed in 5174 survivors of acute myocardial infarction or coronary revascularization (i.e. coronary artery bypass graft surgery or percutaneous coronary interventions), of whom 3811 (73.7%) were at very high risk.
RESULTS: At baseline, the mean patient age was 60.3 years, mean serum value of total cholesterol was 228 mg/dL, and mean LDL-C was 163 mg/dL. Of all CHD patients, approximately 70% did not achieve a serum LDL-C target of <100 mg/dL. Most patients receiving HMG-CoA reductase inhibitor (statin) regimens were treated initially with low- to medium-equipotency regimens and were never titrated to stronger regimens. The vast majority (approximately 94%) of patients at very high risk did not achieve the stringent serum LDL-C target of <70 mg/dL. Patients receiving higher potency statins were significantly more likely to achieve LDL-C goals, whereas those with higher baseline LDL-C levels or Malaysian ethnicity were less likely to achieve LDL-C goals.
CONCLUSIONS: Most CHD patients in the large group of Singapore residents with CHD in the present study did not achieve recommended LDL-C targets. A more effective disease-management approach, including patient education concerning lifestyle modification (e.g. diet, physical activity), efforts to enhance medication adherence, and more effective, well tolerated therapies such as high-equipotency or high-dose statins and statin combination regimens, may be needed to improve achievement of consensus cholesterol targets. This is the first study of cholesterol goal attainment in a large group of Southeast Asians and serves as a baseline for future evaluations in Asian populations.
METHODS: Male subjects included in this study were drawn from those undergoing routine annual medical examinations offered by their employers. Venous blood was obtained from these patients after an overnight fast and from which genomic DNA was extracted. Genotyping was carried out by polymerase chain reaction (PCR) followed by digestion with restriction enzyme NciI. Personal and family medical history of the subjects were also taken.
RESULTS: The genotype distribution of the individuals studied was in accordance to a population at Hardy Weinberg equilibrium. The frequency of the PI(A2) allele was 0.1, 0.01 and 0.01 in the Indians, Malays and Chinese, respectively. The differences in frequencies of the PI(A2) variant are significant among different ethnic groups (P<0.001 for Indians vs. Chinese and Indians vs. Malays).
CONCLUSIONS: We observed a significantly higher frequency of the PI(A2) allele among Indians relative to the Chinese and Malays in Singapore. The effect of this genotype may partially explain the higher rate of ischaemic heart disease seen among Indians compared to the Chinese and Malay ethnic groups.