Therapy

Why?

• Metoprolol reduces recurrent ischaemia , without clearly reducing myocardial infarction. ^a
• Diltiazem reduces chest pain (roughly one fewer episode every 2 days) ^c and is more effective than nitroglycerin . ^a Fewer patients have serious headaches, but more develop AV conduction abnormalities. ^a
• Verapamil or dilitazem reduces myocardial infarction, but there is no clear effect on mortality. ^a

Metoprolol reduces recurrent ischaemia

Patient	Treatment	Comparison	Outcome	CER	RRR (95% CI)	NNT (95% CI)
unstable angina a	metoprolol	placebo	recurrent ischaemia at 48 hours	21%	53% (-3% to 78%)	9 (4 to 380)

Diltiazem reduces myocardial infarction and refractory angina better than nitroglycerin

Patient	Treatment	Comparison	Outcome	CER	RRR (95% CI)	NNT (95% CI)
unstable angina a	iv dilitazem	iv nitroglycerin	MI or refractory angina at 2 days	41%	51% (12% to 73%)	5 (3 to 20)
			refractory angina at 2 days	30%	55% (4% to 79%)	6 (3 to 54)
			serious headache requiring analgesia at 2 days	25%	80% (33% to 94%)	5 (3 to 13)
			AV conduction abnormalities at 2 days	0%		-12 (-75 to -7)

Verapamil or diltiazem reduces myocardial infarction

Patient	Treatment	Comparison	Outcome	CER	RRR (95% CI)	NNT (95% CI)
unstable angina or MI a	verapamil or diltiazem	placebo	myocardial infarction at 6 weeks	7.5%	0.79% (0.67% to 0.94%)	68 (43 to 240)

Cardiovascular disease: verapamil reduces non-fatal myocardial infarction

Patient	Treatment	Comparison	Outcome	CER	NNT (95% CI)
MI, angina or hypertension a	verapamil	placebo	non-fatal myocardial infarction at months	7.4%	64 (38 to 450)

Note:

• Beta-blockers, calcium antagonists and nitrates are not clearly different in reducing myocardial infarction or death from heart disease ^d but more patients stop beta-blockers than calcium-channel blockers due to side-effects. ^a
• There is no clear benefit from starting beta-blockers and calcium-channel blockers together compared with beta-blockers alone ^a
• Calcium-channel blockers do not clearly increase the risk of cancer ^{a b}
• There is no clear benefit in giving dihydropyridine calcium blockers (nifedipine and nicardipine) to patients with unstable angina or MI - they may well be harmful ^a . Specifically short-acting nifedipine increases mortality. ^b

Short-acting nifedipine increases mortality

Patient	Treatment	Comparison	Outcome	CER	OR (95% CI)	NNT (95% CI)
myocardial infarction or angina b	short-acting nifedipine	placebo	death at months	6.6%	1.16 (1.01 to 1.33)	100 (51 to 1600)

• Patients with mild-moderate asthma who take cardioselective beta-blockers have a small initial fall in FEV1 (on average 8%), but are not more likely to report respiratory symptoms. ^a