Background: Cardiac allograft vasculopathy (CAV) is initiated by allograft endothelial injury. We hypothesized that a major mechanism by which cytomegalovirus (CMV) could contribute to CAV is by dysregulation of the endothelial vasomotor response.
Methods: Coronary endothelial vasomotor function was determined in 183 consecutive patients (24+/-33 months after transplantation), and was correlated with recipient and donor CMV serological status before transplantation and with documented CMV infection episodes (CMVpp65Ag+). Serial endothelial function measurements were performed in a subgroup of 53 transplant recipients (1 month and 12 months after transplantation). The composite endpoint of cardiovascular related events and death during a follow-up of 66+/-41 months was analyzed based on the CMV serological status before transplantation.
Results: The medium event-free time for CMV-negative recipients of CMV-positive hearts was 8.1 years compared with 13.3 years for the other groups (P<0.05). Distal epicardial but not microvascular endothelial function was significantly impaired in CMV seronegative recipients of seropositive donor hearts (n=48) compared with all other groups (P<0.01 versus seronegative recipient/seronegative donor; P<0.05 versus seropositive recipient/seronegative donor; P<0.05 versus seropositive recipient/seropositive donor). Distal epicardial endothelial dysfunction was more pronounced in heart transplant recipients with a history of documented CMV infection compared with patients without any documented CMV infection (P<0.01). In a longitudinal subgroup analysis, distal epicardial and microcirculatory endothelial vasomotor response deteriorated significantly in recipients with documented CMV infection (P<0.05 versus baseline) but not in patients without previous CMV infection.
Conclusions: Documented CMV infection episodes in heart transplant recipients are associated with impaired coronary endothelial function. CMV-negative recipients of CMV-positive donor hearts have an impaired distal epicardial endothelial function and an increased incidence of cardiovascular-related events and death during follow-up. CMV infection may contribute to allograft failure by accelerating coronary endothelial dysfunction.