Cardiomyopathies — classification and management

Definition and classification. A cardiomyopathy is a myocardial disorder with structural and functional abnormality not explained by coronary disease, hypertension or valve disease. Morphological types: Dilated (DCM), Hypertrophic (HCM), Restrictive (RCM), Arrhythmogenic right ventricular (ARVC), and unclassified (Takotsubo, left-ventricular non-compaction).

Geriatric relevance. Dilated and hypertrophic cardiomyopathy are important causes of sudden cardiac death in older people after coronary disease. Wild-type transthyretin cardiac amyloidosis (ATTR-wt) is the commonest restrictive cardiomyopathy of old age — suspect it in HFpEF with left ventricular hypertrophy but low-voltage ECG, bilateral carpal tunnel syndrome, lumbar canal stenosis, biceps tendon rupture and intolerance of antihypertensives.

Dilated cardiomyopathy. Dilated left ventricle with systolic dysfunction. Causes: ischaemic, alcohol, chemotherapy (anthracyclines, trastuzumab), thyroid disease, tachycardia-mediated, myocarditis, peripartum. Treatment is four-pillar heart failure therapy — ARNI or ACE inhibitor, beta-blocker, MRA and SGLT2 inhibitor — titrated slowly, with diuretics for congestion.

Hypertrophic cardiomyopathy. Asymmetric septal hypertrophy with dynamic left ventricular outflow tract obstruction; in older adults it may be mistaken for aortic stenosis and is described as idiopathic hypertrophic subaortic stenosis (IHSS). The murmur increases with Valsalva and standing and decreases with squatting; a bisferiens pulse with no aortic regurgitant murmur is a clue. Diagnosis is by echocardiography. Therapy relies on beta-blockers; avoid digoxin, diuretics, nitrates and vasodilators which worsen obstruction. Atrial fibrillation is poorly tolerated and may need cardioversion.

Restrictive cardiomyopathy. Impaired ventricular filling with normal or near-normal ejection fraction and biatrial enlargement. Causes: amyloidosis, haemochromatosis, radiation, sarcoidosis and endomyocardial fibrosis (relevant in India). Diagnosis: echocardiography with apical sparing on strain imaging, cardiac MRI, 99mTc-PYP/DPD bone scintigraphy for ATTR, and exclusion of a monoclonal protein (serum free light chains, immunofixation). Must be distinguished from constrictive pericarditis.

Management principles in older adults. Treat heart failure cautiously with attention to preload dependence; control and anticoagulate atrial fibrillation; correct anaemia and thyroid dysfunction. ICD for sudden death prevention only after weighing life expectancy, frailty and patient wishes. In amyloidosis avoid digoxin, calcium channel blockers and high-dose beta-blockers; use tafamidis as disease-modifying therapy in ATTR-CM. Genetic counselling and family screening for inherited forms.

The 2023 ESC Guidelines on Cardiomyopathies — the first standalone ESC cardiomyopathy guideline — adopt a phenotype-based approach with multimodality imaging and genetic testing for all patients and relatives. For the older patient, disease-modifying therapy for ATTR cardiac amyloidosis has expanded rapidly: after tafamidis (ATTR-ACT), the ATTRibute-CM trial (acoramidis, NEJM 2024) and HELIOS-B (vutrisiran, NEJM 2025) both reduced death and cardiovascular hospitalisation; and mavacamten, a cardiac myosin inhibitor (EXPLORER-HCM), is now approved for symptomatic obstructive HCM.