Clinical Investigation
Hypertrophic Cardiomyopathy
Low Left Atrial Strain Is Associated With Adverse Outcomes in Hypertrophic Cardiomyopathy Patients

https://doi.org/10.1016/j.echo.2019.01.007Get rights and content

Highlights

  • The association of PAF and/or LA remodeling with adverse outcomes in HCM was assessed.

  • PAF was associated with greater degree of LA myopathy, but not adverse outcomes.

  • LA conduit strain ≤10.2% and reservoir strain ≤23.8% were linked to adverse outcomes.

Background

Paroxysmal atrial fibrillation (PAF) and left atrial (LA) structural remodeling are common in hypertrophic cardiomyopathy (HCM) patients, who are also at risk for adverse cardiovascular outcomes.

Objective

We assessed whether PAF and/or LA remodeling was associated with adverse outcomes in HCM.

Methods

We retrospectively studied 45 HCM patients with PAF (PAF group) and 59 HCM patients without atrial fibrillation (AF; no-AF group). LA/left ventricular (LV) function and mechanics were assessed by echocardiography. Patients were followed for development of the composite endpoint comprising heart failure, stroke, and death.

Results

Clinical/demographic characteristics, degree of LV hypertrophy, and E/e′ were similar in the two groups The PAF group had significantly higher LA volume, but lower LA ejection fraction (LAEF), LA contractile, and reservoir strain/strain rate than the no-AF group. During follow-up, 27 patients developed the composite endpoint. Incidence of the composite endpoint was similar in the two groups. Absolute values of 23.8% for reservoir strain and 10.2% for conduit strain were the best cutoffs for the composite endpoint, using receiver operating characteristic analysis. Kaplan-Meier survival analysis showed lower event-free survival in patients with reservoir strain ≤23.8% or conduit strain ≤10.2%. Univariate Cox analysis revealed an association between female sex, LAEF, LA reservoir/conduit strain, and LV global longitudinal strain with the composite endpoint. The association between LA reservoir/conduit strain and the composite endpoint persisted after controlling for age, sex, LAEF, and LV global longitudinal strain.

Conclusions

In this pilot HCM patient study, PAF was associated with a greater degree of LA myopathy, and low LA reservoir and conduit strain were associated with higher risk for adverse cardiovascular outcomes.

Section snippets

Study Population

The HCM Registry is approved by the Institutional Review Board of the Johns Hopkins Hospital. Patients were enrolled in the HCM Registry during their first visit to the Johns Hopkins Hypertrophic Cardiomyopathy Center of Excellence. The diagnosis of HCM was based on the presence of LV hypertrophy (≥15 mm) in the absence of uncontrolled hypertension, valvular heart disease, and HCM phenocopies. Clinical information was collected by a review of electronic medical records. Patients underwent

Clinical Features

We retrospectively studied 104 HCM patients; the mean age was 55 ± 14 years (Table 1). Demographic characteristics and distribution of obstructive/nonobstructive HCM was similar in the PAF (n = 45) and no-AF groups (n = 59). There was no difference in the prevalence of mitral regurgitation in the two groups; three patients in the PAF group had moderate to severe MR, with the remainder having trivial to mild MR. Average follow-up duration was 5.7 ± 3.2 years for the PAF group and 6.0 ± 3.3 years

Discussion

In this retrospective study of 104 HCM patients, we found that that HCM patients with PAF have greater degree of LA myopathy but not a higher incidence of adverse CV events. Notably, low LA conduit and LA reservoir strain were independently associated with higher risk for developing the composite endpoint, composed of HF/stroke/death, after adjusting for LV diastolic function (E/e′) and systolic function (LV-GLS).

Conclusion

In this pilot HCM patient study, PAF was associated with a greater degree of LA myopathy, reflected by greater LA enlargement, lower LAEF, and lower LA reservoir strain/strain rate and LA contractile strain/strain rate, when compared with patients without AF. Low LA conduit strain and LA reservoir strain were associated with a higher risk for developing adverse CV outcomes, after adjusting for LV diastolic function and LV systolic strain.

Acknowledgments

We thank Glenn Lie and Gunnar Hansen (GE Ultrasound, Horten, Norway) for providing the strain analysis software.

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  • Cited by (0)

    The first three authors should be considered the same in author order.

    This work was supported by the John Taylor Babbitt Foundation (Chatham N.J.) and startup funds from the University of California San Francisco Division of Cardiology to M.R.A. Dr. Lu was supported by Taipei Veterans General Hospital-National Yang-Ming University Excellent Physician Scientists Cultivation Program, No. 104-V-A-005. Drs. Vakrou and Ventoulis were supported by fellowships from the Hellenic Cardiology Society.

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