Overview of implantable cardioverter defibrillator and cardiac resynchronisation therapy in heart failure management

Clinical trials have established the benefits of implantable cardioverter defibrillators (ICDs) and cardiac resynchronisation therapy (CRT) in the treatment of heart failure patients. As adjuncts to guideline-directed medical therapy, ICDs confer mortality benefits from sudden cardiac arrest, while CRT reduces mortality, hospitalisation rates and improves functional capacity. This review discusses the use of ICDs and CRT devices in heart failure management, outlining the evidence supporting their use, indications and contraindications.

A practical approach to perioperative management of cardiac implantable electronic devices

With the increased use of cardiac implantable electronic devices (CIEDs), it is increasingly important to recognise the unique challenges involved in the management of patients with CIEDs who are undergoing surgery. Practice advisories and consensus statements have been issued by the American Society of Anesthesiologists and the Heart Rhythm Society, advocating a multidisciplinary approach. This review discusses and presents a practical approach to perioperative CIED management in the Singapore context.

Effect of location of out-of-hospital cardiac arrest on survival outcomes

<p><b>INTRODUCTION</b>This study aims to study how the effect of the location of patient collapses from cardiac arrest, in the residential and non-residential areas within Singapore, relates to certain survival outcomes.</p><p><b>MATERIALS AND METHODS</b>A retrospective cohort study of data were done from the Cardiac Arrest and Resuscitation Epidemiology (CARE) project. Out-of- hospital cardiac arrest (OHCA) data from October 2001 to October 2004 (CARE) were used. All patients with OHCA as confirmed by the absence of a pulse, unresponsiveness and apnoea were included. All events had occurred in Singapore. Analysis was performed and expressed in terms of the odds ratio (OR) and the corresponding 95% confidence interval (CI).</p><p><b>RESULTS</b>A total of 2375 cases were used for this analysis. Outcomes for OHCA in residential areas were poorer than in non-residential areas-1638 (68.9%) patients collapsed in residential areas, and 14 (0.9%) survived to discharge. This was significantly less than the 2.7% of patients who survived after collapsing in a non-residential area (OR 0.31 [0.16 - 0.62]). Multivariate logistic regression analysis showed that location alone had no independent effect on survival (adjusted OR 1.13 [0.32 - 4.05]); instead, underlying factors such as bystander CPR (OR 3.67 [1.13 - 11.97]) and initial shockable rhythms (OR 6.78 [1.95 - 23.53]) gave rise to better outcomes.</p><p><b>CONCLUSION</b>Efforts to improve survival from OHCA in residential areas should include increasing CPR by family members, and reducing ambulance response times.</p>

Coronary artery calcification across ethnic groups in Singapore

<p><b>INTRODUCTION</b>In Singapore, the age-standardised event rates of myocardial infarction (MI) are 2- and 3-fold higher for Malays and Indians respectively compared to the Chinese. The objectives of this study were to determine the prevalence and quantity of coronary artery calcification (CAC) and non-calcified plaques across these 3 ethnic groups.</p><p><b>MATERIALS AND METHODS</b>This was a retrospective descriptive study. We identified 1041 patients (810 Chinese, 139 Malays, 92 Indians) without previous history of cardiovascular disease who underwent cardiac computed tomography for atypical chest pain evaluation. A cardiologist, who was blinded to the patients' clinical demographics, reviewed all scans. We retrospectively analysed all their case records.</p><p><b>RESULTS</b>Overall, Malays were most likely to be active smokers (P = 0.02), Indians had the highest prevalence of diabetes mellitus (P = 0.01) and Chinese had the highest mean age (P <0.0001). The overall prevalence of patients with non-calcified plaques as the only manifestation of sub-clinical coronary artery disease was 2.1%. There was no significant difference in the prevalence of CAC, mean CAC score or prevalence of non-calcified plaques among the 3 ethnic groups. Active smoking, age and hypertension were independent predictors of CAC. Non-calcified plaques were positively associated with male gender, age, dyslipidaemia and diabetes mellitus.</p><p><b>CONCLUSION</b>The higher MI rates in Malays and Indians in Singapore cannot be explained by any difference in CAC or non-calcified plaque. More research with prospective follow-up of larger patient populations is necessary to establish if ethnic-specific calibration of CAC measures is needed to adjust for differences among ethnic groups.</p>