None of the clinical trials of other antiarrhythmic drugs had shown significant benefits from treatment, and a number had even failed to show a positive trend. It was certainly possible that treatment of ventricular premature depolarizations, in itself, did not lead to a reduction in mortality, or even sudden death. The studies that had been done, however, had not adequately addressed the issue. Most of the studies were small and did not select patients on the basis of frequent ectopic beats. Moreover, appropriate drugs in optimal doses may not have been used, and adverse effects may well have outweighed any potential benefit. Poor compliance, perhaps due to adverse effects, may also have limited the opportunity for a beneficial outcome.