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Q1: Definition and classification (2 min)
Examiner: Define dilated cardiomyopathy and outline the 2016 ESC revised definition.
Expected answer: DCM is a disease of the heart muscle characterised by dilatation and systolic impairment of the left (or both) ventricle(s) not explained by abnormal loading conditions (hypertension, valve disease, congenital heart disease) or coronary artery disease sufficient to cause global systolic dysfunction. The 2016 ESC revised definition (Pinto et al.) makes the diagnosis objective: LV end-diastolic dimension more than 117% of the value predicted for age and body surface area by the Henry formula (112% is the 2-SD cut-off; 117% is 2 SD plus 5% and adds specificity) AND LVEF under 45% (or fractional shortening under 25%). A new category — hypokinetic non-dilated cardiomyopathy (HNDC) — covers reduced EF (under 45%) without dilatation, an early or pre-dilated phenotype frequently seen in relatives of DCM patients.
Classify by aetiology (the most clinically useful axis): genetic / familial (30 to 50%), myocarditis, toxic (alcohol, anthracycline), peripartum, tachycardia-induced, infiltrative / metabolic / endocrine (haemochromatosis, sarcoidosis, thyroid, Chagas), and neuromuscular. Distinguish from HFrEF more broadly — DCM is a substrate of HFrEF, not synonymous with it.
Q2: Aetiological work-up (3 min)
Examiner: A 45-year-old man presents with a 4-month history of progressive dyspnoea; echo shows dilated LV with EF 30%. How would you work up the cause?
Expected answer: A structured work-up before accepting "idiopathic":
- History — three-generation family history (SCD under 50, pacemaker/ICD, transplant, unexplained HF), alcohol, recreational drugs, chemotherapy (anthracycline cumulative dose), pregnancy in women, tachyarrhythmia, recent viral illness, travel (Chagas-endemic region), autoimmune disease.
- ECG — LBBB, AV block (suggests LMNA, sarcoid), epsilon waves (ARVC), low voltages (amyloid).
- Echocardiography — LVEDD, EF, regional wall motion, functional MR, RV involvement, thrombus.
- Coronary angiography or CTCA — exclude ischaemic heart disease (the commonest DCM mimic).
- Cardiac MRI — tissue characterisation; LGE pattern: mid-wall septal (DCM), subepicardial inferolateral (myocarditis / sarcoid), patchy with FDG uptake (sarcoid), subendocardial coronary (ischaemia).
- Bloods — FBC, U&E, LFT, TFT (thyroid), ferritin and transferrin saturation (haemochromatosis), HFE gene, ANA and autoimmune screen, serum/urine free light chains (amyloid), HIV.
- Holter monitor — quantify NSVT and PVC burden (tachycardiomyopathy).
- Endomyocardial biopsy — only if giant-cell myocarditis suspected (young, fulminant HF, ventricular arrhythmia, high troponin) or sarcoidosis.
- Genetic testing — targeted next-generation sequencing panel if family history, conduction disease, early onset, or specific phenotypic clues (LMNA — conduction; desmosomal — RV involvement).
- Family screening — clinical evaluation, ECG, echo (± CMR) of all first-degree relatives, repeated every 5 years, or more often if the relative is under 50 or has non-diagnostic abnormalities; cascade genetic testing offered to first-degree adult relatives if a pathogenic variant is identified in the proband.
Q3: Definitive management — four pillars and device therapy (3 min)
Examiner: Outline the pharmacological and device management of chronic stable DCM.
Expected answer: Five layers — treat the cause; four pillars of HFrEF; device therapy; anticoagulation; advanced therapies.
Layer 1 — Treat the cause: alcohol abstinence, tachycardia control, thyroid replacement, iron repletion (IV ferric carboxymaltose), corticosteroids for biopsy-proven sarcoid or autoimmune myocarditis, bromocriptine for peripartum, dexrazoxane / cessation for anthracycline.
Layer 2 — Four pillars of HFrEF (each independently reduces mortality, started together at low dose and titrated to target):
- ARNI (sacubitril/valsartan start 49/51 mg twice daily, target 97/103 mg twice daily) or ACE-inhibitor (ramipril target 5 mg twice daily, enalapril 10 to 20 mg twice daily, lisinopril 20 to 35 mg daily). 36-hour washout for ACEi-to-ARNI switch.
- Beta-blocker — one of the three with a proven mortality benefit: carvedilol 25 mg twice daily (50 mg twice daily if over 85 kg), bisoprolol 10 mg daily, metoprolol succinate 200 mg daily. Nebivolol 10 mg daily is an alternative but has not been shown to reduce mortality, and no beta-blocker has been shown superior specifically in non-ischaemic DCM.
- MRA — spironolactone 12.5 to 50 mg daily (or eplerenone if gynaecomastia). Monitor K+ and creatinine.
- SGLT2 inhibitor — dapagliflozin or empagliflozin 10 mg daily.
Layer 3 — Device therapy: ICD if EF 35% or less, NYHA II to III, after at least 3 months of optimal therapy and expected to survive substantially longer than 1 year with good functional status — by the 2021 ESC heart-failure guideline Class I in ischaemic, Class IIa in non-ischaemic disease, with the DANISH trial caveat in non-ischaemic DCM (shared decision-making; the survival benefit was confined to patients aged 70 or under). CRT is, in the same guideline, Class I if QRS is 150 ms or more with LBBB and EF 35% or less in sinus rhythm, Class IIa for QRS 130 to 149 ms with LBBB or non-LBBB at 150 ms or more, and not indicated below 130 ms. CRT-D preferred unless contraindicated.
Layer 4 — Anticoagulation: AF (by CHA2DS2-VASc), visible LV thrombus, or prior embolism. DOACs are recommended in preference to vitamin-K antagonists in heart failure with AF, except with moderate or severe mitral stenosis or a mechanical valve. A low ejection fraction alone, in sinus rhythm, is not an indication.
Layer 5 — Advanced therapies: cardiac transplantation (peak VO2 under 12 to 14 mL/kg/min, recurrent hospitalisation, inotrope dependence); durable LVAD as bridge or destination; palliative care if not a candidate.
Q4: Complications and prognosis (2 min)
Examiner: What are the complications and prognostic markers of DCM?
Expected answer: Cardiac: progressive heart failure, atrial fibrillation, ventricular arrhythmia and SCD (the leading mode of death in younger patients), LV apical thrombus and systemic embolism, functional MR and TR, right-heart failure, cardiogenic shock. Systemic: cardiorenal syndrome, cardiac cachexia, hepatic congestion (cardiac cirrhosis), renal dysfunction, anaemia and iron deficiency.
Prognostic markers of poor outcome: older age, lower EF, higher NYHA class, raised BNP/NT-proBNP, renal dysfunction, hyponatraemia (advanced disease), anaemia/iron deficiency, right-ventricular dysfunction, mid-wall LGE on CMR (Gulati et al., JAMA 2013 — all-cause mortality HR 2.96, arrhythmic composite HR 5.24), non-sustained VT on Holter, LMNA / FLNC / RBM20 / PLN mutations, and non-recovery of EF. Prognosis has improved steeply with evidence-based therapy: in a single-centre idiopathic-DCM cohort followed across three decades, 8-year transplant-free survival rose from 55% (1978-87) to 71% (1988-97) to 87% (1998-2007). Left ventricular reverse remodelling occurs in about one-third of patients on tailored therapy (89 of 242, 37%) and independently predicts better outcome — but relapse is common if treatment is withdrawn (44% within 6 months in TRED-HF), so therapy continues indefinitely. Recovery is most likely in peripartum, tachycardia-induced, alcoholic, thyroid-related and iron-deficient forms. Family screening of all first-degree relatives is the single most under-applied life-saving intervention and is mandatory in every new DCM diagnosis.