Cardiovascular Risk in Malaysia: causes, consequences and prevention

Cardiovascular disease forms the highest morbidity and mortality worldwide and disproportionately affects low and middle-income developing countries. In developing countries, cardiovascular morbidity and mortality tend to affect the (younger) working adults. This poses a significant burden to the economy. This thesis attempts to investigate the burden of cardiovascular risk factors and disease, and its’ prevention in Malaysia, a middle-income developing country. We described the clustering of cardiovascular risk factors (hypertension, diabetes, hypercholesterolemia and obesity) among the adult population in Malaysia. Overall, 63% had at least one cardiovascular risk factor, 33% had two or more risk factors and 14% had three risk factors or more. Thirty-nine percent of those younger than 30 years had at least one cardiovascular risk factor. These findings highlight that despite current health care prevention programmes, the burden of cardiovascular risk is high and affects a large proportion of the young adults. We also assessed differences in cardiovascular risk factor prevalences and clustering patterns among the various states and federal territories of Malaysia. There was geographical variation in the distribution of risk factors as well as its clustering, with a higher burden in poorer states. Cardiovascular risk prediction and prognostic models that were developed in western populations were assessed in our multi-ethnic Asian population. We validated the Thrombolysis In Myocardial Infarction (TIMI) risk score for patients with St-Elevation Myocardial Infarction (STEMI). And, we compared the utility of the Framingham Risk Score (FRS), high and low risk SCORE (Systematic COronary Risk Evaluation) and the World Health Organization /International Society of Hypertension (WHO/ISH) models. Our study confirmed that the FRS and both SCORE models, but not the WHO/ISH model can be used to discriminate cardiovascular risk in the Malaysian population for both men and women. We assessed the effects of cardiac-care provision and reperfusion strategies (primary-PCI and thrombolytics) in preventing mortality for patients presenting with STEMI in an Asian population. Our findings showed that variation in cardiac-care provision and reperfusion strategy did not adversely affect patient outcomes. Patients with STEMI in Malaysia received good acute cardiac-care irrespective of type of facility, with similar prognoses when given thrombolytic therapy or primary-PCI. In the last part of the thesis, we simulated four screening strategies to identify effective screening strategies for the early detection of high cardiovascular risk patients. Our study showed that a targeted cardiovascular risk-factor screening strategy by defining an age eligibility criteria would be better and a more cost effective method than screening for all ages at a community level. In addition, our study highlighted the need for different screening strategies for men and women due to a significant difference in their overall cardiovascular risk. Based on the studies in this thesis, a cardiovascular epidemic is at hand in Malaysia. Tailored strategies for the prevention and control of cardiovascular disease in and Asian population is warranted.