Prediction of Survival in Asian Patients Hospitalized With Heart Failure: Validation of the OPTIMIZE-HF Risk Score.

BACKGROUND: Risk scores predicting in-patient mortality in heart failure patients have not been designed specifically for Asian patients. We aimed to validate and recalibrate the OPTIMIZE-HF risk model for in-hospital mortality in a multiethnic Asian population hospitalized for heart failure. METHODS AND RESULTS: Data from the Singapore Cardiac Databank Heart Failure on patients admitted for heart failure from January 1, 2008, to December 31, 2013, were included. The primary outcome studied was in-hospital mortality. Two models were compared: the original OPTIMIZE-HF risk model and a modified OPTIMIZE-HF risk model (similar variables but with coefficients derived from our cohort). A total of 15,219 patients were included. The overall in-hospital mortality was 1.88% (n = 286). The original model had a C-statistic of 0.739 (95% CI 0.708-0.770) with a good match between predicted and observed mortality rates (Hosmer-Lemeshow statistic 13.8; P = .086). The modified model had a C-statistic of 0.741 (95% CI 0.709-0.773) but a significant difference between predicted and observed mortality rates (Hosmer-Lemeshow statistic 17.2; P = .029). The modified model tended to underestimate risk at the extremes (lowest and highest ends) of risk. CONCLUSIONS: We provide the first independent validation of the OPTIMIZE-HF risk score in an Asian population. This risk model has been shown to perform reliably in our Asian cohort and will potentially provide clinicians with a useful tool to identify high-risk heart failure patients for more intensive management.

Effect of Myocardial Viability Assessed by Cardiac Magnetic Resonance on Survival in Patients With Severe Left Ventricular Dysfunction.

Background: Myocardial viability assessment in revascularization of ischemic heart failure remains controversial. This study evaluated the prognostic utility of cardiac magnetic resonance (CMR) late gadolinium enhancement (LGE) in ischemic heart failure. Methods and Results: This study retrospectively analyzed subjects with ischemic heart failure and left ventricular ejection fraction (LVEF) ≤35%, who underwent CMR at a single center in 2004-2014 before undergoing coronary artery bypass grafting (CABG) or optimal medical therapy (OMT). Analyses were stratified by treatment. Myocardial segments were deemed non-viable if LGE exceeded 50% wall thickness. Overall and anterior viability were assessed. Outcomes were all-cause mortality, cardiovascular (CV) mortality and major adverse CV events. Among 165 subjects (mean (±SD) age 57.5±8.5 years, 152 males), 79 underwent CABG and 86 received OMT. A greater number of non-viable segments was significantly associated with higher all-cause and CV mortality in the CABG group (adjusted hazard ratios 1.17 [95% confidence interval {CI} 1.01-1.37; P=0.04] and 1.25 [95% CI 1.01-1.56; P=0.045], respectively), but not in the OMT (P>0.05) group. Anterior wall viability did not affect outcomes. Conclusions: The extent of myocardial viability assessed by LGE appeared to identify patients with a differential survival benefit from CABG in this retrospective, small cohort study. These findings raise interesting hypotheses that need to be validated in larger prospective studies.

The Singapore Heart Failure Risk Score: Prediction of Survival in Southeast Asian Patients.

INTRODUCTION: Numerous heart failure risk scores have been developed but there is none for Asians. We aimed to develop a risk calculator, the Singapore Heart Failure Risk Score, to predict 1- and 2-year survival in Southeast Asian patients hospitalised for heart failure. MATERIALS AND METHODS: Consecutive patients admitted for heart failure were identified from the Singapore Cardiac Databank Heart Failure registry. The follow-up was 2 to 4 years and mortality was obtained from national registries. RESULTS: The derivation (2008-2009) and 2 validation cohorts (2008-2009, 2013) included 1392, 729 and 804 patients, respectively. Ten variables were ultimately included in the risk model: age, prior myocardial infarction, prior stroke, atrial fibrillation, peripheral vascular disease, systolic blood pressure, QRS duration, ejection fraction and creatinine and sodium levels. In the derivation cohort, predicted 1- and 2-year survival was 79.1% and 68.1% compared to actual 1- and 2-year survival of 78.2% and 67.9%. There was good agreement between the predicted and observed mortality rates (Hosmer-Lemeshow statistic = 14.36, P = 0.073). C-statistics for 2-year mortality in the derivation and validation cohorts were 0.73 (95% CI, 0.70-0.75) and 0.68 (95% CI, 0.64-0.72), respectively. CONCLUSION: We provided a risk score based on readily available clinical characteristics to predict 1- and 2-year survival in Southeast Asian patients hospitalised for heart failure via a simple online risk calculator, the Singapore Heart Failure Risk Score.

Correlation of the New York Heart Association classification and the cardiopulmonary exercise test: A systematic review.

AIMS: The New York Heart Association (NYHA) classification is frequently used in the management of heart failure but may be limited by patient and physician subjectivity. Cardiopulmonary exercise testing (CPET) provides a potentially more objective measurement of functional status. We aim to study the correlation between NYHA classification and peak oxygen consumption (pVO2) on Cardiopulmonary Exercise Testing (CPET) within and across published studies. METHODS AND RESULTS: A systematic literature review on all studies reporting both NYHA class and CPET data was performed, and pVO2 from CPET was correlated to reported NYHA class within and across eligible studies. 38 studies involving 2645 patients were eligible. Heterogenity was assessed by the Q statistic, which is a χ2 test and marker of systematic differences between studies. Within each NYHA class, significant heterogeneity in pVO2 was seen across studies: NYHA I (n = 17, Q = 486.7, p < 0.0001), II (n = 24, Q = 381.0, p < 0.0001), III (n = 32, Q = 761.3, p < 0.0001) and IV (n = 5, Q = 12.8, p = 0.012). Significant differences in mean pVO2 were observed between NYHA I and II (23.8 vs 17.6 mL/(kg·min), p < 0.0001) and II and III (17.6 vs 13.3 mL/(kg·min), p < 0.0001); but not between NYHA III and IV (13.3 vs 12.5 mL/(kg·min), p = 0.45). These differences remained significant after adjusting for age, gender, ejection fraction and region of study. CONCLUSION: There was a general inverse correlation between NYHA class and pVO2. However, significant heterogeneity in pVO2 exists across studies within each NYHA class. While the NYHA classification holds clinical value in heart failure management, direct comparison across studies may have its limitations.

Correlation of the New York Heart Association Classification and the 6-Minute Walk Distance: A Systematic Review.

BACKGROUND: Functional status assessment is the cornerstone of heart failure management and trials. The New York Heart Association (NYHA) classification and 6-minute walk distance (6MWD) are commonly used tools; however, the correlation between them is not well understood. HYPOTHESIS: We hypothesised that the relationship between the NYHA classification and 6MWD might vary across studies. METHODS: A systematic literature search was performed to identify all studies reporting both NYHA class and 6MWD. Two reviewers independently assessed study eligibility and extracted data. Thirty-seven studies involving 5678 patients were included. RESULTS: There was significant heterogeneity across studies in 6MWD within all NYHA classes: I (n = 16, Q = 934.2; P < 0.001), II (n = 25, Q = 1658.3; P < 0.001), III (n = 30, Q = 1020.1; P < 0.001), and IV (n = 6, Q = 335.5; P < 0.001). There was no significant difference in average 6MWD between NYHA I and II (420 m vs 393 m; P = 0.416). There was a significant difference in average 6MWD between NYHA II and III (393 m vs 321 m; P = 0.014) and III and IV (321 m vs 224 m; P = 0.027). This remained significant after adjusting for region of study, age, and sex. CONCLUSIONS: Although there is an inverse correlation between NYHA II-IV and 6MWD, there is significant heterogeneity across studies in 6MWD within each NYHA class and overlap in 6MWD between NYHA I and II. The NYHA classification performs well in more symptomatic patients (NYHA III/IV) but less so in asymptomatic/mildly symptomatic patients (NYHA I/II). Nonetheless, the NYHA classification is an easily applied first-line tool in everyday clinical practice, but its potential subjectivity should be considered when performing comparisons across studies.