We therefore aimed to investigate the effects of 12 separate antihypertensive drug classes: alpha-adrenoceptor blockers, adrenergic neuron blockers, angiotensin-converting enzyme inhibitors, angiotensin-II receptor blockers, beta-adrenoceptor blockers, centrally acting antihypertensive drugs, calcium channel blockers, loop diuretics, potassium-sparing diuretics and mineralocorticoid receptor antagonists, renin inhibitors, thiazides and related diuretic agents, vasodilators, and their combined effect on AF risk using a drug target MR approach. The gene discussed is ACE; the disease is atrial fibrillation.