Reducing CV risk in diabetes: An ADA update

Should patients with diabetes and heart disease receive antiplatelet therapy?

Yes. The evidence is clear that people with known diabetes and ASCVD benefit from aspirin therapy, according to the 2017 Standards of Care. Clopidogrel 75 mg/d is an appropriate alternative for patients who are allergic to aspirin. Dual antiplatelet therapy (a P2Y12 receptor antagonist and aspirin) should be used for as long as one year after an ACS and may have benefits beyond this period.⁴⁸

Established heart disease

Are there specific recommendations for patients with diabetes and CHD?

According to the ADA Standards, there is good evidence that both aspirin and statin therapy are beneficial for patients with known ASCVD, and that high-intensity statin therapy should be used. In addition, consider ACE inhibitors to reduce the future risk of CV events. In patients with a prior MI, continue beta-blocker therapy for at least 2 years post event.⁴⁹

Which medications should I avoid, or approach with caution, in patients with congestive heart failure (CHF)?

Thiazolidinediones, dipeptidyl peptidase 4 (DPP-4) inhibitors, and metformin all require careful attention. This is especially important to know when you consider that almost half of all patients with T2DM will develop heart failure.⁵⁰

Thiazolidinediones. The 2017 Standards of Care state that patients with diabetes and symptomatic congestive heart failure should not receive thiazolidinediones, as they can worsen heart failure status via fluid retention. As such, they are contraindicated in patients with class III and IV heart failure.⁵¹

DPP-4 inhibitors. The studies on DPP-4 inhibitors and heart failure have had mixed results. The 2013 SAVOR-TIMI (Saxagliptin Assessment of Vascular Outcomes Recorded in Patients with Diabetes Mellitus–Thrombolysis in Myocardial Infarction) 53 trial⁵² showed that patients treated with saxagliptin were more likely to be hospitalized for heart failure than those taking placebo (3.5% vs 2.8%, respectively). However, the 2015 EXAMINE (Examination of Cardiovascular Outcomes with Alogliptin vs Standard of Care)⁵³ trial and the 2015 TECOS (Trial Evaluating Cardiovascular Outcomes with Sitagliptin)⁵⁴ trial evaluated heart failure and mortality outcomes in patients with alogliptin and sitagliptin, respectively, compared to placebo, and did not show a relationship to heart failure.

Metformin may be used in people who have T2DM and stable CHF if their eGFR remains >30 mL/min; it should be withheld from patients with unstable heart failure and those who are hospitalized with CHF.

Are there antihyperglycemic medications that reduce CV morbidity and mortality in those with established ASCVD?

Yes. This year’s ADA Standards indicate that certain glucose-lowering medications—specifically empagliflozin (a sodium–glucose cotransporter [SGLT]-2 inhibitor) and liraglutide (a glucagon-like peptide [GLP]-1 receptor agonist)—have been shown to be beneficial for those with established CVD. According to the 2017 Standards of Care, “In patients with longstanding suboptimally controlled T2DM and established ASCVD, empagliflozin or liraglutide should be considered, as they have been shown to reduce CV and all-cause mortality when added to standard care.”² The studies that provide support for their use are summarized below. Ongoing studies are investigating the CV effects of other agents in these drug classes.

There is good evidence that both aspirin and statin therapy are beneficial for patients with known ASCVD, and that high-intensity statin therapy should be used.

Empagliflozin. The 2015 EMPA-REG OUTCOME (Empagliflozin Cardiovascular Outcome Event Trial in Type 2 Diabetes Mellitus Patients) study⁵⁵ was a randomized double-blind study of empagliflozin vs placebo and usual care in patients with diabetes and established CVD. Over a median follow-up of 3.1 years, treatment with empagliflozin reduced the aggregate outcome of MI, stroke, and CV death by 14%, reduced CV deaths by 38%, and decreased deaths from any cause by 32%. In December 2016, the FDA announced a new indication for empagliflozin: to reduce the risk of CV death in adult patients with T2DM and CVD.⁵⁶

Liraglutide. The LEADER (Liraglutide Effect and Action in Diabetes Evaluation of Cardiovascular Outcome Results: A Long Term Evaluation) trial⁵⁷ was a double-blind randomized trial of liraglutide vs placebo added to usual care in patients with T2DM at high risk for CVD or with existing CVD. More than 80% of the participants had existing CVD including a history of prior MI, cerebrovascular disease, or peripheral vascular disease. After a median follow-up of 3.8 years, the group taking liraglutide demonstrated a 13% reduction in the composite outcome of MI, stroke, or CV death, a 22% reduction in CV death, and a 15% reduction in death from any cause, compared with placebo.⁵⁷

CORRESPONDENCE
Neil Skolnik, MD, Abington-Jefferson Health, 500 Old York Rd, Ste 108, Jenkintown, PA 19046; nskolnik@comcast.net.

The authors thank Sarah Bradley, director, professional engagement & collaboration at the American Diabetes Association, for her editorial and organizational assistance in the preparation of this manuscript.