Objective: The goal of this study was to determine whether the haptoglobin (Hp) genotype was predictive of restenosis and major adverse cardiac events (MACEs) after percutaneous transluminal coronary angioplasty (PTCA) in individuals with diabetes.
Research design and methods: A consecutive series of 935 diabetic patients treated with oral agents and/or insulin were followed for 1 year after PTCA. The primary study end point was angiographic restenosis, MACEs and secondary study end points were defined as target vessel revascularization, myocardial infarction, and death. Two alleles exist at the Hp gene locus, denoted 1 and 2. The Hp genotype (Hp 1-1, Hp 2-1, or Hp 2-2) was determined by PCR.
Results: In multivariate analysis controlling for all known determinants of outcome after PTCA, we found that the Hp genotype was a highly significant independent predictor of MACEs in the 1-year period after PTCA in individuals with diabetes. This was predominantly due to differences in the risk of myocardial infarction during that period: Hp 1-1, 0 of 129 (0%); Hp 2-1, 20 of 424 (4.7%); and Hp 2-2, 32 of 382 (8.4%); P < 0.0001.
Conclusions: The Hp genotype seems to be highly predictive of adverse cardiac events, particularly myocardial infarction, in the 1-year period after PTCA. Determination of the Hp genotype may be useful in the evaluation of new therapies to reduce cardiovascular risk after PTCA.