Chronic angina syndromes

Type	Typical mechanism	Clinical pattern	ECG / stress test / angiography	Usual treatment approach
Stable angina from obstructive CAD	Fixed epicardial atherosclerotic stenosis	Predictable exertional chest tightness, relieved by rest/nitrates	Stress test may show ischaemia; angiography/CCTA shows obstructive coronary disease	Short-acting nitrate for attacks; beta-blocker or calcium-channel blocker first-line; if inadequate, switch/combine, then consider long-acting nitrate, ivabradine, nicorandil, or ranolazine; revascularisation if symptoms persist despite optimal medical therapy 1
Unstable angina	Acute plaque rupture/erosion with transient thrombosis	New, worsening, or rest angina; ACS pattern	Dynamic ECG changes may occur; coronary disease may be present/culprit lesion may be found	Treat as ACS urgently rather than as stable angina 1
Vasospastic angina (Prinzmetal)	Epicardial coronary spasm	Often rest angina, classically nocturnal/early morning; may be episodic	Transient ST elevation or ST depression during pain; coronaries may be non-obstructive unless coexistent CAD	Calcium-channel blocker first-line; nitrates to prevent recurrent episodes; some patients need combination vasodilator therapy 2
Microvascular angina / cardiac syndrome X / INOCA	Coronary microvascular dysfunction and/or endothelial dysfunction	Angina-like chest pain, often in women; may be exertional or prolonged; often less nitrate-responsive	Stress testing may show objective ischaemia (including exercise ECG ST depression) but coronary angiography shows normal or non-obstructive coronaries	Lifestyle + risk-factor control first; continue antianginal therapy only if it improves symptoms; endotype-based symptom treatment may include beta-blockers, CCBs, ranolazine, ACE-I; if vasospasm is present, CCBs and nitrates are favoured 1 2
ANOCA/INOCA (umbrella term)	Angina/ischaemia with no obstructive coronary arteries; includes microvascular dysfunction and vasospasm	Symptoms can overlap; diagnosis often requires considering the endotype	Coronary anatomy non-obstructive; functional testing may define reduced CFR / high microvascular resistance / vasospasm	Treat according to endotype: microvascular dysfunction → beta-blocker/CCB/ranolazine/ACE-I; vasospasm → CCB ± nitrates ± nicorandil; manage risk factors aggressively 2

Key take-home points

Normal coronaries do not exclude ischaemia: that is exactly the scenario in microvascular angina / syndrome X / INOCA 1.
For suspected cardiac syndrome X, NICE says continue drug treatment only if it improves symptoms, and do not routinely offer secondary prevention drugs solely for this diagnosis 1.
If you identify vasospasm, management shifts towards CCBs and nitrates rather than “classic” obstructive-CAD-style antianginals alone 2.

Angina Pectoris

Overview

Drug Therapy

Medication

all patients should receive aspirin and a statin in the absence of any contraindication
sublingual glyceryl trinitrate to abort angina attacks
NICE recommend using either a beta-blocker or a calcium channel blocker first-line based on 'comorbidities, contraindications and the person's preference'
if a calcium channel blocker is used as monotherapy a rate-limiting one such as verapamil or diltiazem should be used
if used in combination with a beta-blocker then use a longer-acting dihydropyridine calcium channel blocker (e.g. amlodipine, modified-release nifedipine)
- remember that beta-blockers should not be prescribed concurrently with verapamil (risk of complete heart block)
if there is a poor response to initial treatment then medication should be increased to the maximum tolerated dose (e.g. for atenolol 100mg od)