Spotlight on predicting cardiovascular events

Predicting cardiovascular events in patients with type 2 diabetes was the focus of multiple recent studies.

Microvascular disease was a predictor of major cardiovascular events in a population-based cohort study from the United Kingdom, published in The Lancet Diabetes & Endocrinology on May 20. Almost 50,000 type 2 diabetes patients were included, 5.8% of whom had a cardiovascular event during a median follow-up of 5.5 years. Retinopathy, peripheral neuropathy, and nephropathy were all significantly associated with cardiovascular events (hazard ratios, 1.39, 1.40, and 1.35, respectively). For patients with 1, 2, or 3 of these microvascular complications versus none, the multivariable-adjusted hazard ratios were 1.32, 1.62 and 1.99, respectively, and thus the risk appeared roughly additive. The results show that each of the studied microvascular diseases “confers at least a similar risk of cardiovascular events as risk factors contained in contemporary risk equations,” the study authors said. This information could be used to reclassify patients for statin therapy, making patients who are high risk based on microvascular factors eligible for high-intensity therapy while moving low-risk patients from high-intensity to moderate-intensity therapy, the authors suggested.

The relationship between cholesterol and vascular events was investigated by another cohort study, conducted in the Netherlands and published by Diabetes Care on May 23. The study included 1,829 patients with type 2 diabetes and either vascular disease or high risk of developing it. Researchers were looking for a relationship between HDL cholesterol and cardiovascular events and mortality. They didn't find one overall, but a subgroup analysis showed that in patients with LDL cholesterol <2.0 mmol/L (<77.3 mg/dL), higher HDL cholesterol was associated with higher risk of all-cause mortality and cardiovascular events (hazard ratios, 1.14 [95% CI, 1.07 to 1.21] and 1.10 [95% CI, 1.07 to 1.21], respectively). This is in contrast to patients with LDL cholesterol between 2.0 mmol/L and 2.5 mmol/L, in whom higher HDL cholesterol was associated with lower risk of cardiovascular events (hazard ratio, 0.85; 95% CI, 0.75 to 0.951). The higher risk in the subgroup of patients with higher HDL cholesterol and LDL cholesterol <2.0 mmol/L was unexpected, according to the study authors, who noted that intensity of lipid-lowering therapy did not influence the association. They offered a number of possible explanations, including the importance of HDL function, statins' effect on hepatic lipase, and alcohol use, and called for research into causality.

Finally, a French study, also published May 23 by Diabetes Care, looked at change in renal function and major cardiovascular events in type 2 diabetes patients. About 1,000 patients who began the study with normal to moderately reduced kidney function were followed for 6.3 years and included in the discovery cohort. Results showed an association between major cardiovascular events and both annual decline in estimated glomerular filtration rate (eGFR) and annual increase in serum creatinine (SCr). After adjustment, researchers calculated that risk of an event was 4.11 times higher in patients whose eGFR dropped more than 5 mL/min/1.73 m² per year and 3.15 times higher in those whose SCr increased more than 14.0 µmol/L per year (>0.16 mg/dL per year) than other studied patients. The results “strongly support the systematic use of serial measurements of SCr and/or eGFR for fine tuning the prognosis of patients with type 2 diabetes,” the study authors said.