In an industry that makes its money by selling more, Pennsylvania-based Geisinger Health System officials gambled three years ago that they could succeed by doing less, but doing it better. The health system devised a 90-day warranty on elective heart surgery, promising to get it right the first time, for a flat fee. If complications arise or the patient returns to the hospital, Geisinger bears the additional cost. The venture has paid off. Heart patients have fared measurably better, and the health system has cut its bypass surgery costs by 15%.