Left atrial dysfunction may precede left atrial enlargement and abnormal left ventricular longitudinal function: a cardiac MR feature tracking study

Abstract

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.

Diagnostic accuracy of Left atrial function and strain for differentiating between acute and chronic myocardial infarction

“…Left atrial strain is signi cantly impaired in both AMI and CMI. It is in agreement with Zhou D's [37] study suggesting that LA deformation-related damage may manifest even sooner than the LV strain in the MI. This result demonstrated that in those individuals, LV strain was not the most reliable parameter for identifying early damage.…”

Tissue tracking of segmental strain as a predictor of provoked dynamic left ventricular outflow tract obstruction

“…LA strain could be a promising biomarker to survey early diastolic dysfunction. 23 Similarly, previous studies had revealed that LA strain could be initiated before clinically apparent LVH in hypertensives. 24 , 25 This may propose an early distinctive abnormal hemodynamics of diastolic function, and hence, we can speculate that DLVOTO may ultimately induce LV diastolic heart failure which could explain the exertional dyspnea in such patients.…”

Predictive value of left atrial strain analysis in adverse clinical events in patients with hypertrophic cardiomyopathy: a CMR study

“…Second, HCM patients may experience progressive LA remodeling and dysfunction [ 34 ]. However, some studies have shown significant differences between HCM patients and healthy control subjects for LA GLS reservoir and conduit, but not LA GLS booster [ 18 , 23 , 35 ]. One possible explanation for this difference is that the preserved LA pumping function is a compensatory mechanism to maintain the stroke volume and left ventricular filling in mild diastolic insufficiency, and its deterioration reflects LA compliance in the "decompensated" phase [ 35 , 36 ].…”

“…However, the three phases of LA strain were not subdivided in this study. Zhou et al [ 23 ] used standard CMR-FT two-chamber, three-chamber, and four-chamber views to assess adverse outcomes in HCM patients. It was shown that LA reservoir strain and booster strain were associated with adverse outcomes.…”