Coronary dilatation after heart transplantation

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.