Prognostic impact of electrocardiographic signs in patients with Type 2 diabetes and cardiovascular disease: results from the PROactive study

Abstract

Aims: Although a resting electrocardiograph is broadly applied in clinical practice for evaluating patients with Type 2 diabetes and cardiovascular disease, the independent prognostic relevance of electrocardiographic signs has not thoroughly been examined.

Methods: Baseline 12-lead electrocardiographs available in 5231 of the 5238 participants of the PROactive trial were analysed for heart rate, heart rate corrected QT-interval, presence of atrial fibrillation/flutter, left axis deviation, right and left bundle branch block. The association of electrocardiographic signs with total mortality, the principal secondary composite endpoint (death, myocardial infarction and stroke) and serious adverse heart failure events was examined by Cox-regression analysis.

Results: Two hundred and twenty-three (4.3%) patients showed atrial fibrillation/flutter, 213 (4.1%) patients had right bundle branch block, 111 (2.1%) patients had left bundle branch block and 706 (13.5%) patients had left axis deviation. Mean cQT-interval was 418 ms (± 25 ms) and mean heart rate was 72/min (± 14/min). In multivariate adjusted analyses, heart rate and cQT-interval were significantly associated with mortality, the composite secondary endpoint and heart failure, whereas right and left bundle branch blocks were significantly associated with heart failure only. Left axis deviation was associated with heart failure and atrial fibrillation/flutter was associated with mortality and heart failure in univariate but not multivariate analyses.

Conclusion: Easily assessable electrocardiographic signs such as heart rate, cQT-interval and bundle branch blocks were predictive for adverse outcome independently of multiple risk factor adjustment and should be considered in clinical care.

Trial registration: ClinicalTrials.gov NCT00174993.