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Coronary dilatation after heart transplantation
Thomas Nickel1, Amir Bigdeli, Franz von Ziegler
1Medizinische Klinik und Poliklinik 1, Campus Großhadern, Ludwig- Maximilians Universität, Munich, Germany. tsnickel@web.de
Insights
Coronary dilatation (CD) occurs in 3.8% of heart transplant recipients, similar to the general population but more diffuse. Patients with CD experience microvascular dysfunction and flow deceleration, yet survival remains unaffected.
Area of Science:
- Cardiology
- Transplantation Medicine
- Vascular Biology
Background:
- Coronary dilatation (CD) incidence in non-transplant populations ranges from 0.2% to 5%.
- Potential endothelial-dependent and -independent causes of CD are suggested.
- The incidence and prognosis of CD post-heart transplantation are currently unknown.
Purpose of the Study:
- To determine the incidence of coronary dilatation (CD) in heart transplant recipients.
- To investigate the characteristics and functional implications of CD in this population.
- To assess the prognostic impact of CD on survival after heart transplantation.
Main Methods:
- Retrospective analysis of coronary angiographies from 688 heart transplant recipients.
- Definition of CD: ≥1.5-fold localized increased vessel diameter or diffuse dilatation (>50% of artery).
- Subgroup analysis (177 patients) included quantitative angiography, microvascular Doppler flow, and intravascular ultrasound.
Main Results:
- CD was detected in 3.8% (26/688) of recipients, associated with stenosing coronary artery disease in 27%.
- Diffuse dilatation (type I-II) was observed in 63% of CD cases, predominantly involving the right coronary artery.
- Patients with CD showed reduced flow velocity and impaired microvascular endothelial-independent function, but no impact on survival.
Conclusions:
- The incidence of CD in heart transplant recipients is comparable to the general population, but with a more diffuse pattern.
- CD in heart transplant patients is linked to microvascular endothelial-independent dysfunction and flow deceleration.
- Coronary dilatation does not appear to negatively impact survival in heart transplant recipients.
Background:
The angiographic incidence of coronary dilatation (CD) in the nontransplant population is approximately 0.2% to 5%. The endothelial-dependent and -independent causes for CD are postulated. So far, the incidence and prognosis of CD after heart transplantation is unknown.
Methods:
We retrospectively analyzed the annual coronary angiographies of 688 heart transplant recipients regarding the incidence of CD (defined as ≥1.5-fold localized increased vessel diameter or diffuse dilatation involving more than 50% of the coronary artery). A subgroup analysis of coronary epicardial (quantitative angiography) and microvascular (doppler flow measurement) vasomotor function in response to acetylcholine (endothelial dependent) and adenosine (endothelial independent) as well as intravascular ultrasound was performed in 177 patients.
Results:
CD was detectable in 26 patients (3.8%) and was associated with stenosing coronary artery disease in 27% of the patients. Segments with CD tended to have less intimal hyperplasia compared with nondilated segments. A diffuse dilatation (type I-II) was present in 63% of the recipients. The right coronary artery was always involved. The patients with CD (5 of 177) showed a 31% reduced flow velocity in the dilated coronaries compared with the nondilated coronary arteries (P=0.03). Microvascular endothelial-independent function was impaired in CD by -29% (coronary flow reserve mean 1.9 vs. 2.7; P=0.04), whereas endothelial-dependent response was unchanged. Epicardial endothelial-dependent and -independent responses were not different between the groups. Incidence of CD was not associated with limited survival.
Conclusion:
The incidence of CD in the nontransplant population is similar to that in the transplanted population. However, the latter shows a more diffuse extent. Heart transplantation patients with CD had microvascular endothelial-independent functional limitations and flow deceleration, whereas survival was not affected.
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