Diastolic Dysfunction of the Cardiac Allograft and Maximal Exercise Capacity

• Published in: The Journal of heart and lung transplantation Vol. 28; no. 5; pp. 434 - 439
• Main Authors: Roten, L., MD, Schmid, J.-P., MD, Merz, F., MD, Carrel, T., MD, Zwahlen, M., PhD, Walpoth, N., MD, Mohacsi, P., MD, Hullin, R., MD
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.05.2009; Elsevier
• Subjects: Adult; Aged; Biological and medical sciences; Cardiology. Vascular system; Diastole - physiology; Echocardiography, Doppler; Exercise Test; Female; Heart Failure - diagnosis; Heart Failure - physiopathology; Heart Transplantation - physiology; Humans; Male; Medical sciences; Middle Aged; Oxygen - blood; Postoperative Complications - diagnosis; Postoperative Complications - physiopathology; Predictive Value of Tests; Prognosis; Surgery; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Surgery of the heart; Systole - physiology; Ventricular Dysfunction, Left - diagnosis; Ventricular Dysfunction, Left - physiopathology; Heart; Physical exercise; Transplantation; Homotransplantation; Phlebology; Treatment; Capacity; Dysfunction; Surgery; Graft; Exercise tolerance test; Circulatory system; Cardiology
• ISSN: 1053-2498; 1557-3117
• DOI: 10.1016/j.healun.2008.12.001

Background Peak oxygen uptake (peak V o2 ) is an established integrative measurement of maximal exercise capacity in cardiovascular disease. After heart transplantation (HTx) peak V o2 remains reduced despite normal systolic left ventricular function, which highlights the relevance of diastolic function. In this study we aim to characterize the predictive significance of cardiac allograft diastolic function for peak V o2. Methods Peak V o2 was measured using a ramp protocol on a bicycle ergometer. Left ventricular (LV) diastolic function was assessed with tissue Doppler imaging sizing the velocity of the early (Ea) and late (Aa) apical movement of the mitral annulus, and conventional Doppler measuring early (E) and late (A) diastolic transmitral flow propagation. Correlation coefficients were calculated and linear regression models fitted. Results The post-transplant time interval of the 39 HTxs ranged from 0.4 to 20.1 years. The mean age of the recipients was 55 ± 14 years and body mass index (BMI) was 25.4 ± 3.9 kg/m2 . Mean LV ejection fraction was 62 ± 4%, mean LV mass index 108 ± 22 g/m2 and mean peak V o2 20.1 ± 6.3 ml/kg/min. Peak V o2 was reduced in patients with more severe diastolic dysfunction (pseudonormal or restrictive transmitral inflow pattern), or when E/Ea was ≥10. Peak V o2 correlated with recipient age ( r = −0.643, p < 0.001), peak heart rate ( r = 0.616, p < 0.001) and BMI ( r = −0.417, p = 0.008). Of all echocardiographic measurements, Ea ( r = 0.561, p < 0.001) and Ea/Aa ( r = 0.495, p = 0.002) correlated best. Multivariate analysis identified age, heart rate, BMI and Ea/Aa as independent predictors of peak V o2. Conclusions Diastolic dysfunction is relevant for the limitation of maximal exercise capacity after HTx.