Ranolazine is an inhibitor of the late sodium current and is used to minimize calcium overload and angina frequency in patients with chronic angina. The RIVER-PCI investigators hypothesized that ranolazine would reduce angina and improve quality of life in patients with incomplete revascularization after percutaneous coronary intervention (PCI). A total of 2,604 of these patients with a history of chronic angina were randomly assigned to receive oral ranolazine or placebo. No significant incremental benefit was associated with adding ranolazine to the standard treatment regimen. Improvements in angina frequency and quality-of-life score were evident in both groups within 1 month of PCI, and were sustained up to 1-year of follow-up. “Our findings,” summarize the investigators, “highlight the difficulty in assessing the clinical significance of incomplete revascularization, since patient-reported angina and quality of life markedly improved within 1 month after PCI. RIVER-PCI clarifies that prescribing ranolazine based on angiographic determinations alone is unsupported.”