BARCELONA – High levels of pro-B-type natriuretic peptide significantly predicted cardiovascular events in patients with type 2 diabetes, a prospective study has found.
Over 6 years, patients with diabetes and high levels of the cardiac protein were more than 50% as likely to have an acute cardiovascular event than were patients without diabetes who had low pro-BNP levels, Dr. Christoph H. Saely said at the annual meeting of the European Association for the Study of Diabetes.
The finding could be useful in risk stratification of patients with diabetes, said Dr. Saely of the Academic Teaching Hospital Feldkirch, Austria.
He and his colleagues followed 750 patients who underwent coronary angiography for the evaluation of established or suspected stable coronary artery disease for a mean of 6 years.
At baseline, the patients’ mean age was 66 years. Most (64%) were men. About 60% were current or past smokers, and 24% had type 2 diabetes.
Generally, those with diabetes had worse markers of cardiac health, including a higher incidence of hypertension (91% vs. 79%); a higher body mass index (29 vs. 27 kg/m2); and worse lipid measurements. At baseline, 65% of those with diabetes had marked coronary artery disease, compared with 50% of those without diabetes – a significant difference.
The baseline pro-BNP level was also significantly higher in the patients with diabetes (mean of 750 pg/mL vs. 500 pg/mL).
Over the follow-up period, there were 119 coronary events (16%), including cardiovascular death (24), nonfatal heart attack (18), and nonfatal stroke (12). There were also 10 coronary artery bypass grafts, 27 percutaneous coronary interventions, and 28 noncoronary revascularizations.
To evaluate the impact of pro-BNP levels on cardiovascular risk, Dr. Saely divided the cohort into four groups according to diabetes and either high or low pro-BNP levels; a low level was less than 314 pg/mL, while a high level was 314 pg/mL or more. Patients were classified into nondiabetes with low pro-BNP (391); nondiabetes with high pro-BNP (182); diabetes with low pro-BNP (109); and diabetes with high pro-BNP (68).
By the end of the study, there had been significantly fewer cardiovascular events among patients with low pro-BNP; 95% of those without diabetes and 90% of those with diabetes were free of such events.
Among those patients who had no diabetes but had a high pro-BNP, 80% were event free by 6 years. But the picture was much worse for patients who had diabetes coupled with a high pro-BNP level, Dr. Saely said. By 6 years, about half had experienced some kind of major cardiovascular event; the excess risk associated with high levels was more than 50%, he said, even after adjustment for age, gender, hypertension, body mass index, and smoking status.
The protein is generally thought of as a marker for heart failure, he added. In patients with long-standing diabetes, he said, it may be associated with metabolically induced cardiac fibrosis.
Dr. Saely had no financial disclosures.