Glycemic control and risk of repeat revascularization

The association between glycemic control after coronary angioplasty and outcomes of the latter is controversial in many studies. We have come to think that the risk lies in suffering from diabetes, as if it was an unmodifiable factor. We have also come to believe that glycemic control can impact microvascular complications while it cannot do much for a recently implanted stent. In that sense, we miss opportunities to provide pertinent advice to improve patient prognosis. 

This study included 980 patients with type 2 diabetes mellitus who underwent coronary angioplasty using drug-eluting stents (DES). Based on 2-year glycosylated hemoglobin A (HbA1c) levels, patients were divided into 2 groups: HbA1c < 7.0 (n = 489) and HbA1c ≥ 7.0 (n = 491). Propensity score-matched analysis was performed and resulted in 322 pairs of patients with same baseline characteristics (except for glycemic level, of course).

The primary endpoint was major adverse cardiac and cerebrovascular events (MACCE), defined as a composite of cardiac death, acute myocardial infarction, repeat revascularization, and stroke.

Also read: “EVOLVE II: Diabetes Substudy: Results at 3 Years after the SYNERGY Stent in Diabetics”.

The 7-year (median follow-up duration was 5.4 years) incidence of MACCE was significantly lower for patients with HbA1c < 7.0 when compared with patients with a higher level (26.9% vs. 40.3%; hazard ratio [HR]: 0.75; 95% confidence interval [CI]: 0.57-0.98; p = 0.03).

The difference persisted after all adjustments; it was fundamentally driven by the rate of repeat revascularization (19.9% vs. 29.5%; HR: 0.66; 95% CI: 0.47-0.93; p = 0.02).

In subgroup analyses, the benefit of glycemic control was significantly more prominent in patients with higher residual SYNTAX score after angioplasty.

Also read: “FFR-Guided Non-Culprit Vessel Revascularization in Primary Angioplasty”.

Conclusion

Glycosylated hemoglobin levels < 7 after coronary angioplasty in patients with type 2 diabetes mellitus are associated with a reduced rate of combined events, particularly a reduction in the rates of repeat revascularization.

Editorial

This study clarified the fact that glycemic control has an impact on events, mainly by reducing the rates of repeat revascularization. While new-generation drug-eluting stents clearly improved outcomes when compared with first-generation stents, diabetes is still one of the most important risk factors for restenosis. In certain studies featuring patients with diabetes, new-generation drug-eluting stents failed to reduce restenosis when compared to first-generation DES.

In consequence, we should not waste any opportunities to reduce restenosis in patients with diabetes, and this work offers one more tool to that end.

Original title: Glycemic Control Status After Percutaneous Coronary Intervention and Long-Term Clinical Outcomes in Patients With Type 2 Diabetes Mellitus.

Reference: Jin Kyung Hwang et al. Circ Cardiovasc Interv. 2017;10:e004157.

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