Summary:
In patients with type 2 diabetes mellitus (T2DM) and stable coronary artery disease, long-term dapagliflozin therapy significantly improved coronary flow reserve (CFR) by 34.4% and reduced epicardial adipose tissue (EAT) thickness by 29.18% compared to placebo in the initial 4-week randomized, double-blind phase prior to crossover, though it was associated with no notable adverse effects reported during the follow-up period.
| PICO | Description |
|---|---|
| Population | Adults with type 2 diabetes mellitus (T2DM) and stable coronary artery disease (CAD) enrolled in the DAPAHEART trial. |
| Intervention | Dapagliflozin 10 mg daily administered for 4 weeks in a randomized phase, followed by long-term treatment up to 4 years post-crossover. |
| Comparison | Placebo during initial 4-week randomized, double-blind period; all placebo patients transitioned to dapagliflozin at study end. |
| Outcome | After 4 years, CFR improved by 34.4% (from 2.15 ± 0.19 to 2.85 ± 0.26, p = 0.001), and EAT thickness decreased by 29.18% (p = 0.03). BMI reductions were noted (p = 0.001), but not significantly correlated with EAT change (R² = 0.0662; p = 0.5), suggesting a weight-independent effect of dapagliflozin on EAT. |
Clinical Context
Coronary microvascular dysfunction, quantified as a reduced coronary flow reserve (CFR), is common in type 2 diabetes even in the absence of obstructive disease and independently predicts adverse cardiac events. Epicardial adipose tissue (EAT) is a metabolically active visceral fat depot that sits in direct contact with the myocardium and coronary arteries, secreting inflammatory mediators that promote microvascular impairment. Dapagliflozin, an SGLT2 inhibitor, lowers glucose through glycosuria but also exerts pleiotropic cardiometabolic effects including natriuresis, weight loss and reduced inflammation. Whether any coronary benefit is mediated by weight loss or by weight-independent pathways has been uncertain. The DAPAHEART follow-up addresses this gap by tracking CFR and EAT thickness in patients with diabetes and stable coronary disease over long-term treatment.
Clinical Pearls
- Marked rise in coronary flow reserve: After 4 years CFR rose by 34.4% (from 2.15 ± 0.19 to 2.85 ± 0.26, p = 0.001), indicating meaningfully improved microvascular function.
- Reduced epicardial fat: EAT thickness fell by 29.18% (p = 0.03), pointing to regression of a pro-inflammatory depot implicated in coronary disease.
- Weight-independent effect: Although BMI also fell (p = 0.001), the change in EAT did not correlate with weight loss (R² = 0.0662; p = 0.5), suggesting dapagliflozin acts on epicardial fat beyond simple weight reduction.
- Reassuring tolerability: No notable adverse effects were reported during the follow-up period, consistent with the established safety profile of the drug class.
Practical Application
Dapagliflozin 10 mg once daily is already a guideline-supported option in type 2 diabetes, particularly where cardiovascular or renal protection is sought, so these mechanistic findings reinforce rather than change prescribing. For patients with diabetes and stable coronary artery disease, the data offer a plausible explanation — improved microvascular flow and reduced epicardial fat — for the cardiovascular benefits seen with the class in outcome trials. Clinicians should still individualise therapy, counsel on volume status, genital mycotic infection and the risk of euglycaemic ketoacidosis, and maintain standard secondary-prevention measures. CFR and EAT are research-grade surrogate measures, so these results should inform mechanistic understanding rather than serve as routine treatment targets in everyday practice.
Broader Evidence Context
The findings dovetail with a large body of evidence that SGLT2 inhibitors improve cardiovascular outcomes in type 2 diabetes; dapagliflozin specifically reduced hospitalisation for heart failure in its dedicated cardiovascular outcome programme and improved outcomes in dedicated heart-failure trials. The mechanisms behind that benefit have been debated, and demonstrating improved coronary flow reserve alongside regression of epicardial fat provides a biologically coherent contribution to the discussion. The weight-independent reduction in EAT is consistent with prior suggestions that the class exerts direct anti-inflammatory and tissue-level effects. Overall the study confirms and helps explain established class benefits rather than introducing a conflicting signal.
Study Limitations
- This was a small mechanistic study focused on imaging surrogates rather than a large clinical-outcomes trial.
- After the 4-week randomised phase all placebo patients crossed over to dapagliflozin, so the long-term comparison lacks a concurrent placebo arm.
- The endpoints, CFR and EAT thickness, are surrogate measures and not hard clinical events such as myocardial infarction or death.
- The BMI–EAT correlation analysis was likely underpowered, so the weight-independent conclusion should be interpreted cautiously.
- Results derive from a selected population with diabetes and stable coronary disease and may not generalise more broadly.
Bottom Line
Long-term dapagliflozin was associated with a substantial improvement in coronary flow reserve and a reduction in epicardial fat that appeared independent of weight loss, with no notable adverse effects. These mechanistic findings strengthen the rationale for SGLT2 inhibition in diabetic patients with coronary disease, but as surrogate endpoints from a small study without a long-term placebo comparison, they support — rather than redefine — current guideline-based use of the drug.
Source: Cinti, Francesca, et al. “Coronary flow reserve increase after 4-year dapagliflozin treatment in patients with type 2 diabetes: the DAPAHEART follow-up study.” Read article here.
