Objectives: Cardiac resynchronisation therapy (CRT) improves morbidity and mortality in heart failure (HF). Impaired endothelial function, as measured by flowmediated dilation (FMD) is associated with increased morbidity and mortality in HF and may help to differentiate responders from non-responders. Methods: 19 patients were recruited, comprising 94% men, mean age 69±8 years, New York Heart Association functional classes II-IV, QRSd 161±21 ms and mean left ventricular ejection fraction 26±8%. Markers of response and FMD were measured at baseline, 6 and 12 months following CRT. Results: 14 patients were responders to CRT. Responders had significant improvements in VO2 (12.6±1.7 to 14.7±1.5 mL/kg/min, p < 0.05), quality of life score (44.4±22.9-24.1±21.3, p < 0.01), left ventricular end diastolic volume (201.5±72.5 mL-121.3 ±72.0 mL, p < 0.01) and 6-min walk distance (374.0 ±112.8 m at baseline to 418.1±105.3 m, p < 0.05). Baseline FMD in responders was 2.9±1.9% and 7.4 ±3.73% in non-responders ( p < 0.05). Conclusions: Response to CRT at 6 and 12 months is predicted by baseline FMD. This study confirms that FMD identifies responders to CRT, due to endotheliumdependent mechanisms alone.
Warriner, D. R., Lawford, P., & Sheridan, P. J. (2016). Measures of endothelial dysfunction predict response to cardiac resynchronisation therapy. Open Heart, 3(1). https://doi.org/10.1136/openhrt-2015-000391