P1384 Longitudinal strain in basal, midventricular and apical segments in aortic stenosis and mitral regurgitation and the relationship to pulmonary capillary wedge pressure at exercise

Funding Acknowledgements

Supported by the Danish Heart Foundation

Background

Two dimensional speckle tracking provide reproducible regional and global assessment of left ventricular (LV) function. Valvular heart disease imposes both pressure overload (aortic stenosis (AS) and volume overload (mitral regurgitation (MR) on the LV. Despite high prevalence of valvular heart disease, little is known about the relationship between longitudinal strain (LS) measures and exercise hemodynamics in the pressure over loaded LV AS and the volume over loaded LV in MR.

Purpose

To describe the relationship between segmental LS in AS and MR according to normal or increased pulmonary capillary wedge pressure with exercise.

Methods

In a cross-sectional study patients with asymptomatic AS (aortic valve area <1 cm2 and peak velocity >3.5 m/s) and patients with primary MR (effective regurgitant orifice > 0.30 cm2) underwent echocardiography and stress test in semi-supine position with invasive hemodynamic assessment using a Swan-Ganz catheter. Echocardiograms were performed at rest on a Vivid 9 (GE, Horten, Norway) and stored for offline analysis. Semi-automatic software (Echopac version 202, GE) was used for LS analysis and recorded using an 18-segment model of the LV followed by segmentation into basal (BAS), midventricular (MID) and apical (API) segments. Semi-supine stress test was performed with increase in workload every third minute until exhaustion; at maximum exercise, pulmonary capillary wedge pressure was measured (maxPCWP). Patients were grouped according to maxPCWP > 28 mmHg (group 1) or ≤ 28 mmHg (group 2). Results are shown as mean ± SD, student’s t-test was used for continues data and pearsons chi-squared test was used for categorical data.

Results

Thirty-five patients with AS (age 73 ± 7.0 years, 74% men), and in 44 patients with MR (age 64 ± 8.8 years, 77% men) were studied. Patients with AS had a global LS of -18.8 ± 3.3% vs. -21.5 ± 3.3% in MR patients (p = 0.001). Basal, midventricular and apical LS was -14.5%±2.2%, -18.4 ± 2.9% and -26.3 ± 5.5% in AS patients and -18.4 ± 2.6%, -21.9 ± 2.9% and -26.7 ± 5.1% in MR patients (p < 0.001, p < 0.001 and 0.442, respectively). The proportion of AS patients that were in group 1(n = 23) were higher than the proportion of MI patients that were in group 1 (n = 19, 66 % vs 42%, p = 0.046). Patients in group 1 had lower LS in all segments (BAS: -15.7 ± 2.8% vs -17.7 ± 3.1%, MID: -19.3 ± 2.9% vs. -21.6 ± 3.4%, API: -26.0 ± 5.0% vs -27.8 ± 5.4%) but only BAS and MID segments were statistically significant(p = 0.005 and p = 0.002, respectively). In both AS and MR, patients in group 1 had lower segmental LS, but only MID LS in MR patients was statistically significant (-20.9%±2.5% vs -22.7 ± 2.9%, p = 0.030).

Conclusion

In patients with AS or MR PCWP above 28 mmHg with exercise was associated with lower LS in BAS and MID segments. This implies that in both pressure and volume overload resting LV function is depressed when patients have abnormally elevated filling pressure with exercise.

Abstract P1384 Figure. Longitudinal strain