Impaired left atrial reservoir strain assessed by cardiovascular magnetic resonance feature tracking was significantly associated with adverse clinical outcomes (HR 0.960) in patients with hypertension and hypertrophic cardiomyopathy without left atrial enlargement.
Cohort (n=180)
No
Does CMR-FT derived left atrial strain predict adverse clinical events in patients with hypertrophic cardiomyopathy or hypertension without left atrial enlargement?
CMR-FT-derived left atrial strain is a sensitive metric for assessing LA dysfunction and predicting prognosis in early-stage hypertension and hypertrophic cardiomyopathy prior to LA enlargement, outperforming LV global longitudinal strain.
Effect estimate: HR 0.960 (95% CI 0.927-0.995)
p-value: p=0.025
BACKGROUND: The role of the dysfunction of left atrium in the occurrence and development of cardiovascular disease has been gradually recognized. We aim to compare the impact on left atrial (LA) function between patients with hypertrophic cardiomyopathy (HCM) and hypertension (HTN) without LA enlargement using cardiovascular magnetic resonance feature tracking (CMR-FT), and if possible, explore the capability of LA function for providing clinical implication and predicting clinical adverse events in the early stage of cardiovascular disease. METHODS: Consecutive 60 HCM patients and 60 HTN patients with normal LA size among 1413 patients who underwent CMR were retrospectively analyzed as well as 60 controls. Left atrial and ventricular functions were quantified by volumetric and CMR-FT derived strain analysis from long and short left ventricular view cines. The primary endpoint was a composite of all-cause death, stroke, new-onset or worsening heart failure to hospitalization, and paroxysmal or persistent atrial fibrillation. RESULTS: Compared to the controls, both HTN and HCM participants had impaired LA reservoir function (εs) and conduit function (εe) with the different stage of LA booster pump dysfunction (εa). LA strain was more sensitive than LV longitudinal strain (GLS) for evaluate primary endpoint (εs: 33.9% ± 7.5 vs. 41.2% ± 14.3, p = 0.02; εe: 13.6% ± 6.2 vs. 17.4% ± 10.4, p = 0.03; εa: 20.2% ± 6.0 vs. 23.7% ± 8.8, p = 0.07; GLS: -19.4% ± 6.4 vs. -20.0% ± 6.8, p = 0.70, respectively). After a mean follow-up of 6.8 years, 23 patients reached primary endpoint. Cox regression analyses indicated impaired LA reservoir and booster pump strain were associated with clinical outcomes in patients at the early stage of HTN and HCM (p < 0.05). CONCLUSIONS: CMR-FT-derived strain is a potential and robust tool in demonstrating impaired LA mechanics, quantifying LA dynamics and underlining the impacts on LA-LV coupling in patients with HTN and HCM without LA enlargement. The corresponding LA dysfunction is a promising metric to assess clinical implication and predict prognosis at the early stage, superior to GLS.
Zhou et al. (2022) conducted a cohort in Hypertrophic cardiomyopathy and hypertension without left atrial enlargement (n=180). Cardiovascular magnetic resonance feature tracking (CMR-FT) derived left atrial strain vs. Healthy controls / Left ventricular global longitudinal strain was evaluated on Composite of all-cause death, stroke, new-onset or worsening heart failure to hospitalization, and paroxysmal or persistent atrial fibrillation (HR 0.960, 95% CI 0.927-0.995, p=0.025). Impaired left atrial reservoir strain assessed by cardiovascular magnetic resonance feature tracking was significantly associated with adverse clinical outcomes (HR 0.960) in patients with hypertension and hypertrophic cardiomyopathy without left atrial enlargement.