Diminished coronary reserve in patients with biopsy-proven inflammatory infiltrates

We tested the hypothesis that patients with biopsy-proven inflammatory infiltrates have an impaired vasodilator capacity of the coronary microvasculation.

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.

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).

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.