The Impact of Diabetes on Haemodynamic and Cardiometabolic Responses in Heart Failure With Preserved Ejection Fraction

Aims Heart failure with preserved ejection (HFpEF) and diabetes mellitus (DM) commonly co-exist. However, it is unclear if DM modifies the haemodynamic and cardiometabolic phenotype in patients with HFpEF. We aimed to interrogate the haemodynamic and cardiometabolic effects of DM in HFpEF. Methods We compared the haemodynamic and metabolic profiles of non-DM patients and patients with DM–HFpEF at rest and during exercise using right heart catheterisation and mixed venous blood gas analysis. Results Of 181 patients with HFpEF, 37 (20%) had DM. Patients with DM displayed a more adverse exercise haemodynamic response vs HFpEF alone (mean pulmonary arterial pressure: 47 mmHg [interquartile range {IQR} 42–55] vs 42 [38–47], p<0.001; workload indexed pulmonary capillary wedge pressure indexed: 0.80 mmHg/W [0.44–1.23] vs 0.57 [0.43–1.01], p=0.047). HFpEF–DM patients had a lower mixed venous oxygen saturation at rest (70% [IQR 66–73] vs 72 [69–75], p=0.003) and were unable to enhance O2 extraction to the same extent (Δ-28% [-33 to -15] vs -29 [-36 to -21], p=0.029), this occurred at a 22% lower median workload. Resting mixed venous lactate levels were higher in those with DM (1.5 mmol/L [IQR 1.1–1.9] vs 1 [0.9–1.3], p<0.001), and during exercise indexed to workload (0.09 mmol/L/W [0.06–0.13] vs 0.08 [0.05–0.11], p=0.018). Conclusion Concurrent diabetes and HFpEF was associated with greater metabolic responses at rest, with enhanced wedge driven pulmonary hypertension and relative lactataemia during exercise without appropriate augmentation of oxygen consumption.