San Francisco, CA—New insights into the predictors of outcomes in patients with diabetes were provided by several studies and registries presented at the 2013 American College of Cardiology annual meeting by investigators from around the world.
Diabetes Linked to Angina Pre/Post-MI
An unexpected finding from the TRIUMPH Prospective Cohort Study was that patients with diabetes had a significantly greater prevalence of angina before and after an acute myocardial infarction (MI) than patients without diabetes—49% versus 42%, respectively (P <.001).
After the acute MI, the association between angina and diabetes was stronger over time, as well as in patients without multivessel disease, presumably because of the diffuse nature of coronary artery disease in patients with diabetes.
The Seattle Angina Questionnaire was used at admission, and at 1, 6, and 12 months after an acute MI in this analysis of 3612 patients, 30% of whom had diabetes, from 24 hospitals across the United States.
The investigators stated that this finding is “contrary to conventional wisdom” regarding the prevalence of angina in patients with and without diabetes, and its prevalence had not been previously quantified. Furthermore, they found that diabetic patients took more antianginal medications, thus the association may be underestimated in this analysis.Angina after an acute MI leads to repeat hospitalizations and higher costs.
Hyperglycemia Predictor of Acute Kidney Injury
Hyperglycemia at hospital admission after an acute MI was found to be an independent predictor of acute kidney injury in a study conducted at the National Cerebral and Cardiovascular Center in Japan. In addition, the incidence of kidney injury increased as admission glucose levels increased.
Of the 760 patients in the study, 13% had an acute kidney injury, defined as an absolute increase in serum creatinine ≥0.3 mg/dL or a ≥50% relative increase within 48 hours of hospitalization; 53% of the patients with kidney injury had diabetes. In-hospital mortality was significantly higher (24%) in the patients with kidney injury compared with only 3% in the patients without.
Diabetes and Renal Failure
The Acute Coronary Syndrome (ACS) Registry of the large-scale, multinational Euro Heart Survey revealed that renal failure is an independent predictor of in-hospital mortality, but diabetes was not, in patients who had a non–ST-elevation ACS. The ACS Registry comprises 121,582 patients.
Of the 12,833 patients with non–ST-elevation ACS, 8% had renal failure and 4% of these patients also had diabetes.
The in-hospital rate of death was 7.9% in patients with renal failure alone, 8.3% with renal failure plus diabetes, 3.2% with diabetes alone, and 2.7% in patients without renal failure or diabetes. The patients with renal failure were older (aged >75 years) and had a higher incidence of previous MI or revascularization.
Also from the ACS Registry, the investigators found that for ST-elevation MI (STEMI), diabetes and renal failure were independent predictors of in-hospital mortality. Of the 8646 patients with STEMI in the registry, 96% had diabetes and 20% of them also had renal failure. The odds ratio (OR) for in-hospital mortality on multivariate analysis was 1.78 for renal failure alone, 1.27 for renal failure plus diabetes, and 1.34 for diabetes alone.
Of note, the OR for female patients was 1.34 and for age >75 years was 3.22. The patients with renal failure had the highest rate of death, at 18.4% with renal failure plus diabetes and 17.4% with renal failure alone compared with 9.2% in patients with diabetes alone and 5.9% without renal failure or diabetes.
Heart Failure and Impaired Glucose Intolerance
An analysis from the Cardiovascular Health Study, a population-based cohort of women aged >65 years in the United States, showed that heart failure is a risk factor for diabetes. It has been known that the presence of diabetes increases the risk of heart failure.
Heart failure significantly increased the risk for impaired glucose tolerance (OR, 2.18) and overt diabetes (OR, 4.78) developing within 3 to 4 years. This association remained after adjustment for a variety of factors. The same increased risk was seen in the patients with impaired glucose tolerance at baseline, although it was not statistically significant.