Left ventricular dysfunction assessed by speckle-tracking strain analysis in patients with systemic sclerosis: relationship to functional capacity and ventricular arrhythmias.

OBJECTIVE: Systemic sclerosis (SSc) is a connective tissue disease characterized by vascular inflammation and fibrosis. Visceral involvement, including cardiac manifestations, can lead to severe clinical complications, such as congestive heart failure, arrhythmias, and sudden death. Conventional echocardiography parameters have limited sensitivity to detect subtle myocardial dysfunction in patients with SSc. The aim of this study was to assess, using novel speckle-tracking strain analysis, the presence of myocardial dysfunction in patients with SSc, and to investigate its relationship to functional capacity and ventricular arrhythmias.
METHODS: A total of 104 patients with SSc (mean ± SD age 54 ± 12 years, 77% female) were included and underwent cardiopulmonary exercise testing, 24-hour electrocardiography (EKG) Holter monitoring, and transthoracic echocardiography. For comparison, 37 matched healthy control subjects were included.
RESULTS: The total patient population consisted of 51 patients with limited cutaneous SSc and 53 with diffuse cutaneous SSc. Peak VO(2) was a mean ± SD 91 ± 20% predicted, and 28 patients had abnormal findings (ventricular tachycardia or ventricular ectopics >100/day) on EKG Holter monitoring. Patients with SSc, as compared with controls, had impaired global longitudinal and circumferential strains (mean ± SD -18.2 ± 1.8% versus -21.3 ± 1.7% and -18.2 ± 2.3% versus -21.3 ± 2.1%, respectively; each P < 0.01), but there was no difference in the left ventricular ejection fraction between patients and controls (mean ± SD 63.5 ± 7.2% versus 64.6 ± 4.4%; P = 0.20). In patients with SSc, global longitudinal and circumferential strains each correlated with the peak VO(2) (r = -0.46 and r = -0.41, respectively; both P < 0.01), and multivariate analysis confirmed the independent association of each strain measure with the peak VO(2). Compared to SSc patients with normal results on EKG Holter monitoring, SSc patients with abnormal results showed impaired global longitudinal strains (-18.5 ± 1.5% versus -17.1 ± 2.1%; P < 0.01) and circumferential strains (-18.7 ± 2.0% versus -17.3 ± 2.5%; P = 0.01), and each strain measure was independently associated with abnormal Holter findings.
CONCLUSION: Speckle-tracking strain analysis can detect subtle myocardial dysfunction in patients with SSc. Importantly, decreased global longitudinal and circumferential strains are associated with lower functional capacity and rhythm disturbances in patients with SSc.