We did not find evidence for causal effects (or a protective effect) from the other 8 antihypertensive drug classes (adrenergic neuron blockers, angiotensin-converting enzyme inhibitors, angiotensin-II receptor antagonists, centrally acting antihypertensives, loop diuretics, potassium-sparing diuretics and aldosterone antagonists, renin inhibitors, and thiazides) on AF risk (Table; Figure 2). This evidence concerns the gene REN and atrial fibrillation.