The Effect of Carbenicillin and Aspirin in the Prevention of Experimental Sudden Death in the Dog

Abstract

Carbenicillin (C) and aspirin (A) inhibit platelet (P) aggregation (AG) and prolong the bleeding time. Previous studies in our laboratory demonstrated a 55% incidence of sudden death (SD) in dogs following acute coronary embolization. Since P AG may contribute to myocardial ischemia in this model, we studied the effect of C and A-induced P dysfunction on the incidence of SD. 40 dogs were randomized to treatment with saline or C 750mg/Kg/day subqx5, and 40 dogs ware randomized to placebo or A 600mg p.o./day × 5. 17 other dogs were treated with estradiol cypionate (E) lmg/Kg/TM. P AG was inhibited in A and C treated animals, but normal in control dogs. Thrombocytopenia (P < 15,000/dl) was induced in all E treated dogs. Glass bead coronary artery embolization was performed in anesthetized dogs. 19 of 38 control dogs died within 15 min after embolization while only 2/22 C treated dogs, 5/20 A treated dogs and 0/17 E treated dogs died in 15 min. Survival of C and E-treated dogs was significantly greater (p<0.01) than controls, while survival of A-treated dogs was not significantly better (p<0.25) than placebo. These studies demonstrate that SD following glass bead coronary embolization can be prevented by pretreatment with C. This protective effect is probably related to C-induced P dysfunction since marked thrombocytopenia offers similar protection. Further studies of the role of P AG and P-inhibitory drugs in SD are indicated.