Related Experiment Videos
Coronary vasodilator reserve after human orthotopic cardiac transplantation
A L McGinn1, R F Wilson, M T Olivari
1Department of Medicine, University of Minnesota, Minneapolis.
Insights
Cardiac transplant recipients generally maintain normal coronary vasodilator reserve, crucial for blood flow, unless left ventricular hypertrophy or wall motion issues are present. This indicates preserved microvascular function post-transplant in most cases.
Area of Science:
- Cardiology
- Transplantation Immunology
- Vascular Physiology
Background:
- Cardiac transplantation can lead to coronary atherosclerosis and microvascular injury.
- Assessing coronary vascular function is vital after heart transplant.
Purpose of the Study:
- To determine if orthotopic cardiac transplantation impairs coronary vasodilator reserve.
- To evaluate the capacity of coronary vasculature to vasodilate and conduct hyperemic blood flow post-transplant.
Main Methods:
- Measured maximal coronary vasodilator reserve (CVDR) in 25 cardiac allograft recipients and 20 normal subjects.
- Utilized coronary Doppler catheter and intracoronary papaverine for CVDR measurement.
- Assessed left ventricular wall thickness echocardiographically and epicardial coronary anatomy by quantitative coronary angiography.
Main Results:
- CVDR was normal in transplant recipients without rejection, normal left ventricular function, or hypertrophy (n=16).
- CVDR remained normal even in recipients with moderate epicardial coronary atherosclerosis (n=5).
- Reduced CVDR was observed in recipients with left ventricular hypertrophy (n=2/4) and regional wall motion abnormalities (n=1).
Conclusions:
- Orthotopic cardiac transplantation does not impair coronary vasodilator reserve in the absence of rejection, hypertrophy, or wall motion abnormalities.
- Preserved coronary microvascular function is typical post-transplant when these complications are absent.
- Left ventricular hypertrophy and regional wall motion abnormalities may negatively impact coronary vasodilator reserve after cardiac transplantation.
Abstract:
Cardiac transplantation is frequently associated with accelerated coronary atherosclerosis and immune-mediated microvascular injury. To determine if orthotopic cardiac transplantation impairs the capacity of the coronary vasculature to vasodilate and conduct hyperemic blood flow, maximal coronary vasodilator reserve was measured in 25 cardiac allograft recipients with no evidence of rejection 6-57 months after transplantation and in 20 normal subjects. Left ventricular wall thickness was assessed echocardiographically, and epicardial coronary anatomy was evaluated by quantitative coronary angiography. Coronary vasodilator reserve (CVDR) was measured in all patients with a coronary Doppler catheter and a maximally vasodilating dose of intracoronary papaverine. CVDR measured in the transplant recipients with normal coronary arteries, left ventricular function, and wall thickness (5.0 +/- 0.3 [mean +/- SEM] peak/resting velocity; range, 3.8-7.3; n = 16) was not different from that of normal subjects (4.8 +/- 0.2; range, 3.7-8.3). CVDR in the five cardiac allograft recipients with diffuse coronary atherosclerosis producing 30 +/- 5% narrowing (range, 25-38%) of epicardial vessel diameter also was normal (5.1 +/- 0.3; range, 4.3-6.2; n = 5). The CVDR was reduced, however, in two of the four cardiac allograft recipients with left ventricular hypertrophy. In the only transplant recipient in whom a regional wall motion abnormality was present, CVDR was abnormal in the vascular distribution of the hypokinetic wall segment (1.8) but was normal in the artery that supplied normally functioning myocardium (4.0). These findings demonstrate that in the absence of allograft rejection, acquired left ventricular hypertrophy, and regional wall motion abnormalities, coronary vasodilator reserve is normal after orthotopic human cardiac transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)