Dilated cardiomyopathy: causes, family screening, recovery — structured written assessment

SAQ 1 (10 marks)

Practice scenario. A 36-year-old woman presents with breathlessness. Echo shows a dilated left ventricle with LVEF 32%; she has no coronary artery disease, normal blood pressure and no valve disease. Her father died suddenly at 44 years of age with DCM found at post-mortem, and she has two children aged 14 and 17 and a 33-year-old brother.^[1]

1. Give the ESC 2023 definition of DCM and the echo thresholds that define LV dilatation in an adult female. (2)^[1]
2. Why does ESC 2023 consider her DCM familial even before genetic testing? (1)^[1]
3. Give the ESC 2023 row on genetic testing in her as the index patient, with class and level, and the ESC 2026 heart failure row with its class and level. (2)^[1][2]
4. Genetic testing finds a pathogenic LMNA variant. What does ESC 2023 recommend for her adult brother and what should be considered for her children? Give classes. (2)^[1]
5. Give the ESC 2023 Table 21 annual SCD rate and the SCD predictor for LMNA. (1)^[1]
6. Her brother carries the variant and has a normal phenotype. Give the ESC 2023 follow-up row for him with class and level, and the proposed screening interval. (2)^[1]

Model answers — SAQ 1

1. LV dilatation and systolic dysfunction unexplained solely by abnormal loading conditions or CAD (1 mark).^[1] In an adult female by echo, an LV end-diastolic diameter >52 mm and an LVEDV index ≥62 mL/m² (1 mark).^[1]
2. Without conclusive genetic information in a family, ESC 2023 considers DCM familial if one or more first- or second-degree relatives have DCM, or when an otherwise unexplained SCD has occurred in a first-degree relative at any age with an established diagnosis of DCM; her father meets either criterion, and either is accepted (1 mark).^[1]
3. ESC 2023: genetic testing is recommended in patients fulfilling diagnostic criteria for cardiomyopathy when it enables diagnosis, prognostication, therapeutic stratification or reproductive management, or cascade evaluation of relatives who would otherwise be enrolled into long-term surveillance (Class I, Level B) (1 mark).^[1] ESC 2026 heart failure gives the same row for patients with established HF (Class I, Level C) (1 mark).^[2]
4. Brother: cascade genetic testing with pre- and post-test counselling is recommended for adult at-risk relatives once a P/LP variant is found (Class I, Level B) (1 mark).^[1] Children: cascade testing with counselling should be considered in paediatric at-risk relatives, weighing the cardiomyopathy, expected age of onset, presentation in the family and clinical or legal consequences (Class IIa, Level B) (1 mark).^[1]
5. LMNA: annual SCD rate 5–10%, with the estimated 5-year risk of life-threatening arrhythmia from the LMNA risk score as the predictor (1 mark).^[1]
6. Multiparametric clinical evaluation with ECG and cardiac imaging and long-term follow-up in first-degree relatives with the same disease-causing variant (Class I, Level B) (1 mark).^[1] In a family affected by cardiomyopathy, proposed screening of carriers of P/LP variants associated with cardiomyopathies every 1–3 years with ECG and echo (plus additional tests where appropriate) before 60 years of age, then every 3–5 years (1 mark).^[1]

SAQ 2 (10 marks)

Practice scenario. A 52-year-old man had DCM diagnosed 2 years ago with LVEF 25%. On foundational medical therapy he is now asymptomatic, LVEF is 54%, LV volumes are normal and NT-proBNP is 180 ng/L. No reversible cause was found. He asks whether he can stop his medicines.^[10][2]

1. How do AHA/ACC/HFSA 2022 and ESC 2026 define his improvement? (2)^[4][2]
2. Give the ESC 2026 and AHA/ACC/HFSA 2022 rows on continuing therapy, with class or COR. (2)^[2][4]
3. Describe the design and main result of TRED-HF. (3)^[10]
4. Give the ESC 2026 row on gradual discontinuation of therapy, with class and level, and say whether it applies to him. (2)^[2]
5. Which genotype does ESC 2023 link with LVEF recovery? (1)^[1]

Model answers — SAQ 2

1. AHA/ACC/HFSA 2022: HFimpEF, a previous LVEF ≤40% and a follow-up LVEF >40% (1 mark).^[4] ESC 2026: improved LVEF, an absolute increase of at least 10% to a value above 40% (often normal) (1 mark).^[2]
2. ESC 2026: continuation of FMT at the highest tolerated doses is recommended 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) (1 mark).^[2] AHA/ACC/HFSA 2022: in 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) (1 mark).^[4]
3. Open-label, pilot, randomised trial of phased withdrawal of heart failure medications in previously DCM patients now asymptomatic, with LVEF improved from <40% to ≥50%, normalised LVEDV and NT-proBNP <250 ng/L (1 mark).^[10] 51 patients enrolled April 2016 to August 2017: 25 to withdrawal and 26 to continued treatment (1 mark).^[10] Over the first 6 months, 11 (44%) of those assigned to withdrawal met the primary endpoint of relapse versus none who continued (Kaplan-Meier 45.7%; p=0.0001) (1 mark).^[10]
4. ESC 2026: gradual discontinuation of FMT under frequent clinical, laboratory and imaging surveillance may be considered in highly selected patients who are asymptomatic with complete normalization of LV function and volume as well as natriuretic peptide levels after specific treatment of reversible causes of HF, to accommodate patient preference (Class IIb, Level C) (1 mark).^[2] It does not apply to him: no reversible cause was found, so the row’s condition of specific treatment of a reversible cause is not met, and continuation applies (1 mark).^[2]
5. TTN-truncating variants (1 mark).^[1]