LISBON – The sodium-glucose co-transporter 2 (SGLT-2) inhibitor dapagliflozin (Farxiga) posed a lower risk of cardiovascular events and all-cause mortality in patients with type 2 diabetes mellitus (T2DM) compared with dipeptidyl peptidase-4 inhibitors in a large real-world, observational study.
In CVD-REAL NORDIC, treatment with the SGLT-2 inhibitor reduced the incidence of major cardiovascular adverse events by 21% as compared to DDP-4 inhibitors (hazard ratio, 0.79; 95% confidence interval, 0.67-0.94; P = .006).
Anna Norhammar, MD, PhD, of the Institute of Medicine, Cardiology Unit, at Karolinska Institutet in Stockholm, presented the findings at the annual meeting of the European Association for the Study of Diabetes.
She said: “These results are in line with previous clinical trials and meta-analyses, but extend the results to a broader CV risk population and with a commonly used comparator.”
Indeed, the findings build on those from the widely reported EMPA-REG Outcome (New Engl J Med. 2015;373;2117-8) and CANVAS (New Engl J Med. 2017;377:644-7) randomized controlled trials. These trials respectively showed empagliflozin and canagliflozin significantly reduced the risk for MACE and heart failure in patients with T2DM versus placebo. As the majority of patients in these trials had established CV disease, this suggested a class effect for SGLT2 inhibitors, Dr. Norhammar explained.
CVD-REAL NORDIC is part of a larger, multinational, observational, comparative effectiveness study looking at the real-world effect of SGLT2 inhibitors versus other glucose-lowering drugs on CV outcomes in patients with T2DM. Altogether around 90,000 patients have been recruited in Sweden, Norway, and Denmark.
Previously, Dr. Norhammar and co-investigators have reported that SGLT2 inhibitors lowered MACE (HR, 0.78; 95% CI 0.69–0.87, P less than .0001) and heart failure hospitalization (HR, 0.70; 95% CI 0.61–0.81, P less than .0001) relative to all glucose-lowering drugs (Lancet Diabetes Endocrinol. 2017;709–17).
“However, the comparator group used in that study, other [glucose-lowering drugs], consisted of almost 50% patients with T2DM treated with insulin or sul[f]onylureas,” they wrote in Diabetes, Obesity and Metabolism (8 Sep., doi: 10.1111/dom.13077). Insulin or sulfonylureas, they add, “have been shown to have increased associated CV risks” compared with DPP4 inhibitors and it is “not fully clear to what extent this could have influenced risk estimates.”
Furthermore, the CVD-NORDIC investigators note that the comparator group reflected real-world practice and it is important to look at treatment strategies more specifically, hence why they decided to do an analysis comparing SGLT2 and DPP4 inhibitors.
The study population for the current analysis consisted of 40,909 patients with T2DM who were newly initiated on either dapagliflozin (n=10,227) or a DPP4 inhibitor (n=30,682) between 2012 and 2015. The mean age was 61 years, and around 23% had prior CV disease and 5% had previous heart failure.
After a mean follow-up of 11.3 months, 177 MACE events had occurred among the 10,227 dapagliflozin-treated patients and 695 among the 30,681 DPP4 inhibitor-treated patients, giving respective event rates of 1.86 and 2.34 per 100 patient years. MACE was defined as a composite of nonfatal myocardial infarction, nonfatal stroke, and CV mortality.
“Dapagliflozin is the most commonly used SGLT2 inhibitor in the Nordic countries,” Dr. Norhammar said, explaining why this particular SGLT2 inhibitor was used in the analysis.
While there was a clear benefit of using dapagliflozin over DPP4 inhibitors in terms of MACE, heart failure hospitalization, and all-cause mortality, there was a “neutral” effect on atrial fibrillation and severe hypoglycaemia, with respective HRs of 0.92 (95% CI 0.76–1.12; P = .41) and 0.94 (95% CI 0.74–1.19; P = .62).
Dr. Norhammar said these “neutral results for atrial fibrillation and severe hypoglycaemia,” were “in line with expectations, and suggest a low likelihood of confounding.”
As this was an observational study, one of the limitations is that could be confounding factors that could not be adequately matched in the analysis. The events were not adjudicated and the study didn’t look at safety.
Dr. Norhammar noted that the results of the DECLARE-TIMI 58 trials were now needed to see if the potential CV benefits of using an SGLT2 inhibitor over other gluc0se-lowering medications might extend into patients at lower CV risk.
AstraZeneca supported the study.
Dr. Norhammar disclosed acting as a consultant to and receiving honoraria from AstraZeneca, Boehringer-Ingelheim, Eli Lilly, Novo Nordisk, and MSD Sweden.