What Is Refractory Cardiac Failure?

To the Editor: The authors of “Treatment of Refractory Heart Failure with Infusion of Nitroprusside” (N Engl J Med 291: 587–592, 1974) have given no proof that their patients were indeed refractory to their previous digitalis and diuretic therapy. “Refractory” should indicate that the patients were resistant to the maximum therapeutic effect of their previous medication. In the absence of measured drug levels or apparent toxicity an alternate assumption that the subjects selected had an inadequate dose of digitalis or diuretic, or both, cannot be ruled out. A recent article¹has shown that 33 per cent of a study group.