Chronotropic incompetence, echocardiographic abnormalities and exercise intolerance in renal transplant recipients.
BACKGROUND
Chronotropic incompetence (CI) is an independent predictor of cardiovascular events and overall mortality. The prevalence and significance of CI in renal transplant patient has not been examined.


METHODS
38 non-heart failure renal transplant recipients were recruited for a transthoracic echocardiogram and treadmill stress test using the modified Bruce protocol.


RESULTS
15 patients (39.5%) had CI (defined as failure to reach 85% of the maximum age-predicted heart rate, or <8 0% of predicted heart rate reserve). CI patients had higher left ventricular (LV) mass (216.5 ± 56.1 vs. 183.1 ± 40.0 g, p = 0.04), increased septal wall thickness (11.7 ± 1.4 vs. 10.7 ± 1.1 mm, p = 0.03) and posterior wall thickness (10.9 ± 1.9 vs. 9.5 ± 1.7 mm, p = 0.02). At multivariate analysis, CI was associated with elevated serum creatinine [odds ratio (OR) 1.04, p = 0.03] and increased LV mass (OR 1.03, p = 0.03). CI was associated with shorter exercise duration (3.53 ± 2.20 vs. 8.08 ± 2.34 min, p < 0.01) and lower metabolic equivalents (5.40 ± 2.05 vs. 9.82 ± 2.39, p < 0.01). At multivariate analysis, exercise duration was negatively associated with CI (β = -0.54, p < 0.01).


CONCLUSIONS
CI is present in approximately 40% of asymptomatic renal transplant recipients and is associated with reduced exercise tolerance, left ventricular hypertrophy, and worse allograft function .
Department of Medicine, University of Hong Kong, Queen Mary Hospital, Pokfulam Road, Hong Kong, China.
Maggie Kam Man
MK
Ma
Ming Lang
ML
Zuo
Desmond Yat Hin
DY
Yap
Maggie Ming Yee
MM
Mok
Lorraine Pui Yuen
LP
Kwan
Gary Chi Wang
GC
Chan
David Chung Wah
DC
Siu
Tak Mao
TM
Chan
D000328:Adult; D003404:Creatinine / Q000097:blood; D004452:Echocardiography; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000000981:diagnostic imaging / Q000503:physiopathology*; D007668:Kidney / Q000503:physiopathology; D016030:Kidney Transplantation; D008297:Male; D055686:Metabolic Equivalent; D008875:Middle Aged
D003404:Creatinine