Decreased Left Atrial Reservoir Strain Is Associated with Adverse Outcomes in Restrictive Cardiomyopathy

Figures

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  Figure 1. Flow chart of restrictive cardiomyopathy patients’ inclusion and study design. A total of 98 consecutive patients were included in the study after searching our CMR database for patients with clinical diagnosis of restrictive cardiomyopathy and excluding 4 patients with non-diagnostic image quality. A qualitative and quantitative assessment of cardiac MR followed by collection of demographics and comorbidities was performed. CMR = cardiac magnetic resonance; LA = left atrium; LGE = late gadolinium enhancement; LV = left ventricle; RV = right ventricle.

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  Figure 2. A 63-year-old man with RCM. (a) LA endocardial contour was traced at end-systole (i.e., LA end-diastole). The LA function was evaluated using feature-tracking analysis on four-chamber (a) and two-chamber (b) views. The zero reference was set at end-diastole. LA strain was measured at end-systole; the first peak (A-orange line) corresponds with LA reservoir strain; the second peak (B-green line) corresponds to contractile strain; and the difference between the reservoir and contractile strain (blue arrow line C) corresponds to conduit. Average LA strain was calculated as the mean value of the two-chamber and four-chamber views.

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  Figure 3. Boxplots of LA reservoir strain in RCM who experienced death (a) and composite events of death and cardiovascular hospitalizations (b). (a) LA reservoir strain is significantly decreased in patients who died (labeled 1) (p = 0.002). (b) LA reservoir strain is significantly decreased in patients who experienced the composite endpoint of death or cardiovascular hospitalizations (labeled 1) (p = 0.0008). LA = left atrium; RCM = restrictive cardiomyopathy.

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  Figure 4. Representative case of RCM patient who died. (a) A 72-year-old female with multiple myeloma and hypertension referred for cardiac magnetic resonance to evaluate infiltrative cause of restrictive cardiomyopathy. Late gadolinium enhancement image does not show positive signal enhancement of the left ventricular myocardium. Patient’s left ventricular systolic function was 45% and LA reservoir strain was 14%. Patient expired six months after the CMR was performed. (b) A 62-year-old woman with multiple myeloma and hypertension referred for CMR to evaluate for underlying cause of restrictive cardiomyopathy. Late gadolinium enhancement image showed positive global subendocardial late gadolinium enhancement of the left and right ventricular myocardium. Patient’s left ventricular systolic function was 45% and left atrial function by LA reservoir strain was 14%. Patient expired two weeks after this CMR. CMR = cardiac magnetic resonance; LA = left atrium.

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  Figure 5. Kaplan–Meier plots of RCM patients’ survival and composite events by using mild, moderate, and severe LA functional impairment based on left atrial reservoir strain. (a) Patients in the lowest tertile with LA reservoir strain of <15% experienced death at earlier time points than patients with left atrial function >15% (p = 0.008). (b) Patients in the lowest tertile with LA reservoir strain of <15% experienced composite events of death and cardiovascular hospitalizations at earlier time points than patients with left atrial function >15% (p = 0.002). Left atrium = LA.