Diabetes is an independent risk factor for cardiovascular morbidity and mortality in patients with heart failure regardless of ejection fraction -- but more strongly so for those with preserved ejection fraction -- investigators in Europe and North America report.
The prognostic importance of ventricular function in diabetic patients with heart failure (HF) is unknown. To investigate this issue, Dr. John J. V. McMurray, at the University of Glasgow, UK, and his associates analyzed outcomes for 7599 patients with symptomatic chronic HF enrolled in a clinical trial of candesartan in heart failure.
Sixty percent of the participants had an ejection fraction of 40 per cent or less, and 28 per cent were diagnosed with diabetes.
"A novel finding was that diabetes conferred a greater increase in relative risk (and similar substantial increase in absolute risk) of the primary outcome of cardiovascular death or HF hospitalization in preserved ejection fraction HF when compared with low ejection fraction HF," the investigators report in the June issue of the European Heart Journal.
Adjusted hazard ratios for patients with diabetes versus those without diabetes for the combined outcome during a median follow-up of 38 months were 1.60 for patients with low ejection fraction and 2.0 for those with preserved ejection fraction (p = 0.0009).
For HF hospitalization specifically, the adjusted HRs for diabetics compared with nondiabetics were 1.64 in those with low ejection fraction and 2.04 in those with preserved ejection fraction (p = 0.0029).
In absolute terms, Dr. McMurray and his group report, "Patients with preserved ejection fraction HF and diabetes had a greater rate of HF hospitalization than patients with low ejection fraction HF and no diabetes (27.8 vs 21.7 per cent)."
A similar pattern was observed for cardiovascular and all-cause mortality, though the difference between those with and those without diabetes was not statistically significant.
The investigators note that the adverse effects of diabetes -- including decreased arterial compliance, worse endothelial function, renal angiopathy, autonomic dysfunction, and susceptibility to atrial fibrillation -- "may also be relatively more important in patients with predominantly diastolic dysfunction."
