Prognostic impact of late gadolinium enhancement granularity using cardiovascular magnetic resonance in end‑stage hypertrophic cardiomyopathy

Presenting Author(s)

• 

  Julien HUDELO, MD

  Cardiologist
  Centre Hospitalier Universitaire Amiens Picardie
  Amiens, Picardie, France

Primary Author(s)

• 

  Julien HUDELO, MD

  Cardiologist
  Centre Hospitalier Universitaire Amiens Picardie
  Amiens, Picardie, France

Co-Author(s)

• JG

  Jérome Garot, MD, PhD

  Cardiologist
  Institut Cardiovasculaire Paris Sud, Hôpital Privé Jacques CARTIER, Ramsay Santé, 91300, Massy, France, France
• ST

  Solenn Toupin, PhD

  Clinical scientist
  Siemens Healthineers
  Bordeaux, Aquitaine, France
• TG

  Trecy Gonçalves, MD

  Cardiologist
  Hôpital Lariboisière, AP-HP, Paris, France, France
• AU

  Alexandre Unger, MD

  Cardiologist
  Hôpital Lariboisière AP-HP
  Paris, Ile-de-France, France
• JF

  Jeremy FLORENCE, MD

  Cardiologist
  Lariboisière hospital, APHP, Paris, France.
  Paris, Ile-de-France, France
• JD

  Jean Guillaume Dillinger, MD, PhD

  Cardiologist
  Lariboisière Hospital – APHP, Paris, France., France
• CT

  Christophe Tribouilloy, MD, PhD

  Cardiologist
  CHU Amiens, France
• AH

  Alexis Hermida, MD

  Cardiologist
  CHU Amiens, France
• VB

  Valérie Bousson, MD, PhD

  Radiologist
  Lariboisière Hospital – APHP, Paris, France., France
• 

  Theo Pezel, MD, PhD

  Cardiologist
  Hôpital Lariboisière – APHP, Paris, France
  Paris, Ile-de-France, France
• yB

  yohann Bohbot, MD, PhD

  Cardiologist
  CHU Amiens, France

Background: End-stage hypertrophic cardiomyopathy (HCM) is a distinct and advanced form of HCM, defined by a left ventricular ejection fraction (LVEF) < 50% and associated with a markedly poor prognosis. Evidence on the prognostic relevance of LGE and its key features in end-stage HCM remains limited. We aim to evaluate the prognostic value of the LGE granularity model including its location, extent and pattern in end-stage HCM patients.

Methods: All patients referred for cardiovascular magnetic resonance (CMR) assessment of HCM at three French university hospitals between 2008 and 2024 were retrospectively screened. All patients with HCM and LVEF < 50% were included. The “LGE granularity model” was defined as a model combining LGE extent (focal vs. multifocal involvement), location (septal vs. other), and pattern (subepicardial vs. midwall). The primary endpoint was all-cause mortality using the National Registry of Death.

Results: Among 2,873 patients with HCM, 691 (24%) with end-stage HCM were included (53±7 years, 54% male). At the time of CMR, 30% of patients presented with heart failure symptoms classified as NYHA > II and 26% had a history of atrial fibrillation. After a median follow-up of 9 years (IQR 6–11), 226 patients died (32%). LGE was observed in 259 patients (37%) and was strongly associated with mortality (HR: 3.37, [95% CI: 2.57-4.42], p< 0.001), even after adjustment for traditional prognostic factors (HR: 1.52, [95% CI: 1.07-2.18], p=0.02). In sub-group analysis, LGE presence was associated with all-cause mortality in patients with LVEF >40% (HR: 3.32 [95% CI: 1.61-6.45], p< 0.001) but was not in patients with LVEF < 40% (HR: 0.98 [95% CI: 0.73-1.32], p=0.90). Each LGE granularity component was independently associated with mortality after adjustment with traditional prognostic factors: LGE extent (HR: 2.85, [95% CI: 1.03-7.85], p=0.02), septal location (HR: 1.73, [95% CI: 1.10-2.73], p< 0.001), and midwall pattern (HR: 4.15, [95% CI: 1.79-9.61], p< 0.001). The LGE granularity model improved risk reclassification and discrimination compared to traditional prognostic factors (NRI: 32%; IDI: 10%, both p< 0.001; global Chi-square: 139 to 167, p< 0.001).

Conclusion: In this large multicenter cohort of end-stage HCM patients, the LGE granularity model integrating the LGE extent, location, and pattern provided strong and independent prognostic value beyond traditional prognostic factors.

Univariable and multivariable Cox regression analysis in end-stage HCM patients to predict all-cause mortality (Nf691).

	Univariable analysis		Multivariable analysis
	Hazard Ratio (95% CI)	p-value	Hazard Ratio (95% CI)	p-value
Model 1† (traditional prognostic factors):
Age	1.03 (1.01 - 1.06)	0.02	1.02 (0.99 - 1.04)	0.21
Male	1.12 (0.81 - 1.56)	0.49	1.09 (0.77 - 1.55)	0.61
Diabetes	1.50 (0.93 - 2.41)	0.11	1.90 (1.14 - 3.18)	0.02
Hypertension	0.91 (0.64 - 1.30)	0.60	0.91 (0.62 - 1.33)	0.63
Current or previous smoker	0.75 (0.51 - 1.10)	0.13	0.85 (0.56 - 1.29)	0.44
Renal failure*	0.96 (0.49 - 1.88)	0.89	0.66 (0.32 - 1.39)	0.26
Atrial fibrillation history	1.39 (1.00 - 1.94)	0.06	1.04 (0.72 - 1.51)	0.82
Heart failure hospitalization history	1.08 (0.75 - 1.56)	0.68	1.18 (0.80 - 1.74)	0.41
LVEF per 5%	0.62 (0.57 - 0.68)	< 0.001	0.65 (0.58 - 0.73)	< 0.001
LVEDVi per 10 mL/m²	1.73 (1.56 - 1.92)	< 0.001	1.20 (1.02 - 1.40)	0.02
RV dysfunction	1.84 (1.28 - 2.63)	0.002	1.70 (1.16 - 2.50)	0.009
Model 2b‡ (LGE granularity):
Extent
Focal involvement	Ref.	Ref.	Ref.	Ref.
Multifocal involvement	7.33 (2.71 - 19.8)	< 0.001	2.85 (1.03 - 7.85)	0.02
Location
Any other location	Ref.	Ref.	Ref.	Ref.
Septal location	4.98 (3.44 - 7.22)	< 0.001	1.73 (1.10 - 2.73)	< 0.001
Pattern
Subepicardial LGE	Ref.	Ref.	Ref.	Ref.
Midwall LGE	2.79 (1.30 - 5.99)	< 0.001	4.15 (1.79 - 9.61)	< 0.001

Survival curves of all-cause mortality in end-stage HCM patients stratified by the presence of LGE and “LGE granularity model” parameters.
Survival curves of all-cause mortality in end-stage HCM stratified by LGE presence and LVEF