EurekAlert -- Although statins are widely used to prevent heart attacks, strokes, and other cardiovascular disorders, new research shows that the class of drugs may actually have negative effects on some cardiac patients. A new study presented at CHEST 2009, the 75th annual international scientific assembly of the American College of Chest Physicians (ACCP), found that statins have beneficial effects on patients with systolic heart failure (SHF), but those with diastolic heart failure (DHF) experienced the opposite effect, including increased dyspnea, fatigue, and decreased exercise tolerance.