Dilated cardiomyopathy: causes, family screening, recovery — structured viva

Stem

Practice viva. The examiner asks how you define and investigate dilated cardiomyopathy, how you look after the family, how you decide on an ICD and what you tell a patient whose LVEF has improved.^[1][2]

Branch A — Definition and cause

Examiner: A 45-year-old man drinks heavily and has a dilated, poorly contracting left ventricle. Is this alcoholic cardiomyopathy?^[1]

Strong answer:

• ESC 2023 defines DCM as LV dilatation and systolic dysfunction unexplained solely by abnormal loading conditions or CAD, so coronary disease and loading conditions are excluded first.^[1]
• Alcohol is in its list of toxic causes, but an acquired cause does not exclude an underlying causative variant, and a variant may need an acquired trigger to manifest.^[1]
• Causative variants occur in 10–15% of alcoholic DCM, and genetic testing can be beneficial in alcohol-induced DCM too.^[1]
• Key elements of the work-up for every patient with DCM include clinical and family history, laboratory tests, ECG, Holter monitoring, cardiac imaging and genetic testing; contrast-enhanced CMR is recommended at initial evaluation (ESC 2023, Class I, Level B), and, in patients with established HF, in suspected cardiomyopathy or where the underlying aetiology of HF is uncertain, if further characterization is likely to add value to patient care (ESC 2026, Class I, Level C).^[1][2]

Follow-up: What can CMR tell you here?^[1]

• Oedema, which may suggest a myocarditic or inflammatory cause, and the presence, extent and pattern of LGE, which may exclude infarction and point to specific causes such as septal mid-wall LGE in LMNA carriers (ESC 2023).^[1]
• LGE distribution and extent hold prognostic value for arrhythmia and heart failure severity.^[1]

Branch B — The family

Examiner: His panel shows a pathogenic DSP variant. What happens to his family?^[1]

Strong answer:

• Genetic counselling for the family (ESC 2023, Class I, Level B), and pre- and post-test counselling for everyone tested (Class I, Level B).^[1]
• With this P/LP variant, cascade genetic testing with pre- and post-test counselling is offered to adult at-risk relatives, starting with first-degree relatives if available (Class I, Level B), and should be considered in paediatric at-risk relatives, considering the underlying cardiomyopathy, expected age of onset, presentation in the family and clinical or legal consequences (Class IIa, Level B).^[1]
• Following cascade testing, clinical evaluation using a multiparametric approach that includes ECG and cardiac imaging, and long-term follow-up, is recommended in first-degree relatives who carry the same disease-causing variant as the proband (Class I, Level B); first-degree relatives without a phenotype who do not carry it are discharged from follow-up but advised to seek re-assessment if they develop symptoms or when new clinically relevant data emerge in the family (Class I, Level C).^[1]
• Contrast-enhanced CMR should be considered in genotype-positive, phenotype-negative relatives (ESC 2023, Class IIa, Level B), and ESC 2023 says cardiac MRI should also be considered in carriers with normal function whose variant raises SCD risk, such as DSP.^[1]

Follow-up: And if no variant had been found?^[1]

• Initial clinical evaluation with ECG and cardiac imaging of first-degree relatives (Class I, Level C), with regular long-term evaluation to be considered (Class IIa, Level C); diagnostic genetic testing of phenotype-negative relatives is not recommended without a confident genetic diagnosis in the family (Class III, Level C).^[1]

Branch C — Sudden death

Examiner: On optimal therapy for 4 months, he has NYHA class II symptoms and LVEF 40%, with LGE on CMR. Does he need an ICD?^[1]

Strong answer:

• DSP is a high-risk genotype in ESC 2023 Table 21 (annual SCD rate 3–5%; predictors LGE on CMR and LVEF <45%).^[1]
• With a high-risk genotype and LVEF >35% in the presence of additional risk factors, ESC 2023 says an ICD should be considered (Class IIa, Level C); for DSP its Table 21 lists LGE on CMR and LVEF <45% as predictors of SCD.^[1]
• The decision is shared, evidence-based and reflects his preferences, beliefs, circumstances and values (ESC 2023, Class I, Level C), with counselling on inappropriate shocks, complications and driving beforehand (Class I, Level C), and an ICD only with expected good quality survival >1 year (Class I, Level C).^[1]

Follow-up: What does DANISH tell you?^[9]

• In a randomised controlled trial of 1116 patients with symptomatic systolic HF (LVEF ≤35%) not caused by coronary artery disease, an ICD versus usual clinical care was not associated with a significantly lower rate of death from any cause over a median 67.6 months (21.6% versus 23.4%; HR 0.87), but sudden cardiac death occurred in 4.3% versus 8.2% (HR 0.50).^[9]
• ESC 2023 reports that, in the trials without CAD, subgroup analysis suggested a survival benefit in patients ≤70 years.^[1]

Branch D — Improvement

Examiner: Two years on, his LVEF is 55% and he wants to stop his tablets.^[2][10]

Strong answer:

• ESC 2026 recommends continuation of FMT at the highest tolerated doses in all patients with HF, including those who become asymptomatic or with LVEF improvement, to reduce the risk of HF hospitalization and death (Class I, Level C).^[2]
• AHA/ACC/HFSA 2022: in patients with HFimpEF after treatment, GDMT should be continued to prevent relapse of HF and LV dysfunction, even in patients who may become asymptomatic (COR 1, LOE B-R).^[4]
• In TRED-HF, an open-label pilot randomised trial in asymptomatic patients with previous DCM whose LVEF had improved from <40% to ≥50%, with normalised LVEDV and NT-proBNP <250 ng/L, 11 of 25 (44%) assigned to phased withdrawal met the primary endpoint of relapse over the first 6 months, against none of the 26 who continued; its authors concluded that treatment should continue indefinitely until robust predictors of relapse are defined.^[10]