Objective: We tested the hypothesis that patients with biopsy-proven inflammatory infiltrates have an impaired vasodilator capacity of the coronary microvasculation.
Methods: In 80 patients with clinically suspected inflammatory heart disease, coronary regulation was assessed with the argon method (1) at rest and maximal coronary flow (V(cor)/V(max)) and (2) at rest and minimal coronary resistance (R(cor)/R(min)) both before and after dipyridamole (0.5 mg/kg body weight) treatment.
Results: Compared to patients without evidence of myocardial inflammation in endomyocardial biopsy (n = 51) but similar demographic characteristics, patients with biopsy-proven inflammatory infiltrates (n = 29) showed significantly reduced maximal coronary flow (286 +/- 122 vs. 189 +/- 78 ml/min x 100 g; p = 0.001) and minimal coronary resistance was increased (0.40 +/- 0.17 vs. 0.60 +/- 0.27 mm Hg x min x 100 g/ml(-1), p = 0.001). The coronary reserve in patients with inflammatory infiltrates was markedly reduced (3.5 +/- 1.1 to 2.4 +/- 0.81, p = 0.001).
Conclusion: Patients with biopsy-proven inflammatory infiltrates have a diminished coronary reserve due to reduced coronary vasodilator capacity. This may be due to the involvement of the intramural coronary vasculature in inflammatory heart disease.