Atrial and Ventricular Strain Imaging Using CMR in the Prediction of Ventricular Arrhythmia in Patients with Myocarditis

Abstract

(1) Objective: Myocarditis can be associated with ventricular arrhythmia (VA), individual non-invasive risk stratification through cardiovascular magnetic resonance (CMR) is of great clinical significance. Our study aimed to explore whether left atrial (LA) and left ventricle (LV) myocardial strain serve as independent predictors of VA in patients with myocarditis. (2) Methods: This retrospective study evaluated CMR scans in 141 consecutive patients diagnosed with myocarditis based on the updated Lake Louise criteria (29 females, mean age 41 ± 20). The primary endpoint was VA; this encompassed ventricular fibrillation, sustained ventricular tachycardia, nonsustained ventricular tachycardia, and frequent premature ventricular complexes. LA and LV strain function were performed on conventional cine SSFP sequences. (3) Results: After a median follow-up time of 23 months (interquartile range (18-30)), 17 patients with acute myocarditis reached the primary endpoint. In the multivariable Cox regression analysis, LA reservoir (hazard ratio [HR] and 95% confidence interval [CI]: 0.93 [0.87-0.99], p = 0.02), LA booster (0.87 95% CI [0.76-0.99], p = 0.04), LV global longitudinal (1.26 95% CI [1.02-1.55], p = 0.03), circumferential (1.37 95% CI [1.08-1.73], p = 0.008), and radial strain (0.89 95% CI [0.80-0.98], p = 0.01) were all independent determinants of VA. Patients with LV global circumferential strain > -13.3% exhibited worse event-free survival compared to those with values ≤ -13.3% (p < 0.0001). (4) Conclusions: LA and LV strain mechanism on CMR are independently associated with VA events in patients with myocarditis, independent to LV ejection fraction, and late gadolinium enhancement location. Incorporating myocardial strain parameters into the management of myocarditis may improve risk stratification.

Keywords: cardiovascular magnetic resonance; myocardial strain; myocarditis; outcomes; ventricular arrhythmia.

Figure 1

Flowchart of patients included in the study.

Figure 2

Event-free survival probability by prognosticators values during follow-up. Panels (A–F) display three-dimensional survival areas for left atrial (LA) reservoir, LA conduit, and LA booster strain measures and global measures of left ventricular (LV) circumferential, LV radial, and LV longitudinal strain illustrating the arrhythmia-free survival probability (y-axis) at various time points during follow-up (x-axis) up to 12 months across a range of prognosticators values (color-coded). For instance, panel (A) demonstrates a higher probability of event-free survival within 12 months for higher LA reservoir values, while panel (D) correlates higher LV global longitudinal strain with improved event-free survival outcomes.

Figure 3

Spline curve showing the hazard ratio for the occurrence of ventricular arrhythmic (VA) events at follow-up according to left ventricular global circumferential strain (LV GCS). This curve (blue line) shows the association of hazard ratio for the incidence of VA events along with 95% confidence intervals (blue bands) across a range of values of LV GCS at the time of the cardiac MR. The value of LV GCS in which the predicted HR is ≥1 can be used as a cut-off to stratify the population in high- and low-risk (dashed orange line).

Figure 4

Arrhythmia-free survival analysis according to left ventricular global circumferential strain (LV GCS) > −13.3% vs. GCS ≤ −13.3%. Kaplan-Meier curves for the occurrence of ventricular arrhythmic (VA) events at follow-up show that patients with LV GCS > −13.3% are more likely to experience VA events.