A new dawn for heart failure treatment? -2
BRIGHAM AND WOMEN’S TRANSATLANTIC DIALOGUES ON CONTROVERSIES IN CONTEMPORARY CARDIOLOGY
Himself a cardiologist, Cowie works together with respiratory physicians, as they share an interest in sleep apnoea or sleep disordered breathing (SDB). Cowie presented the latest data on central sleep apnoea (CSA). Sleep apnoea is common in HF, and the more severe the clinical picture, the higher the chance that it concerns CSA. In CSA, oscillation of ventilation is seen, as a result of respiratory drive that comes and goes, which is distinct from obstructive sleep apnoea.
It is well established based on epidemiological studies that sleep apnoea in HF patients is associated with worse prognosis. The SERVE-HF trial therefore set out to study whether adding adaptive servo-ventilation (ASV) to guideline-based medical management benefits patients with systolic HF in terms of survival and CV outcomes. The primary endpoint time to first event of all-cause death, life-saving cardiovascular intervention or unplanned hospitalisation for worsening chronic HF was neutral.
More strikingly, the secondary endpoint of all-cause death showed a higher risk in those in whom CSA was treated by means of ASV, as compared with those on control therapy (HR: 1.28, 95%CI: 1.06-1.55, P=0.01). The effect of treating CSA was even stronger for CV death, with mortality being 34% higher in the ASV group than in the control group (95%CI: 1.09-1.65, P=0.006).15
*While patients often feel better when their central sleep apnoea is treated with adaptive servo-ventilation, the intervention actually puts the patients at risk*
This unexpected harmful effect could not be explained by subgroup characteristics, and the hazard of ASV was worse with lower ejection fraction. A posthoc analysis revealed that the risk of sudden death, thus CV death without prior hospitalisation for deterioration of HF, was even more increased (HR: 2.59, 95%CI: 1.54-4.37, P<0.001). When ejection fraction drops below 30%, the patient has an over five-fold risk of sudden death.16 Thus, while patients often feel better when their CSA is treated with ASV, the intervention actually puts patients at serious risk.
Martin R Cowie, MD – Professor of Cardiology, Imperial College London, United Kingdom