Alterations in left atrial pressure and compliance during balloon mitral valvuloplasty

Invasive hemodynamics are equivocal for functional outcomes after MitraClip

Objectives

To evaluate invasive hemodynamics in assessing MC therapy success as well as evaluate its effectiveness as a predictor of functional outcomes.

Background

Mitral regurgitation grade is a poor predictor of functional outcomes after a MitraClip. There is a paucity of data on invasive hemodynamics as a predictor of outcomes.

Methods

Sixty-nine patients underwent MC between 2015 and 2018 at the University of Minnesota Medical Center and were retrospectively analyzed. Invasive hemodynamics were performed before and after device deployment with transesophageal echocardiographic guidance. Statistical analysis was performed using STATA version 16. Student's t test was used for continuous variables and Pearson's chi-squared test for categorical variables. Mann-Whitney test was performed for continuous variables where data were not normally distributed. Logistic and linear regression were used to investigate relationships between variables and outcomes.

Results

A total of 69 patients were included in the study. The mean age was 83 (75-87) years and 38 (55%) were male. Eighty-one percentage had >/= NYHA III symptoms. Eighty-seven percentage had severe MR. Pulmonary capillary wedge pressure was 20 (15-24). Overall, there was significant improvement in left atrial pressure including mean left atrial pressure index, MR, and NYHA class after MC (<.001). There was no significant association between invasive hemodynamics (including left atrial mean pressure index or its reduction rate) and functional outcomes (p = NS). MR grade was also not predictive of functional outcomes.

Conclusion

Left atrial pressure may not be a significant predictor of functional outcomes, and, in isolation, may not be an improvement over MR grade.

Contribution of the left atrial remodeling to the elevated pulmonary capillary wedge pressure in patients with WHO Group II pulmonary hypertension

BACKGROUND

The contribution of progressive left atrial (LA) enlargement to elevated pulmonary capillary wedge pressure (PCWP) in patients with WHO Group II pulmonary hypertension (PH) has not been well studied. We hypothesized that progressive LA enlargement is associated with increased PCWP.

METHODS

A cross-sectional retrospective cohort consisted of 166 patients with HF and WHO Group II PH, confirmed by right heart catheterization (RHC). LA anteroposterior dimension and volume were measured on TTE. PCWP and other hemodynamic parameters were measured by RHC. Univariate and multivariate logistic regression models were used for analysis.

RESULTS

LA enlargement was associated with advanced age, increased BMI, and LV ejection fraction < 40%. PCWP was progressively increased in patients with dilated LA: 16.9 ± 7.4 mmHg in normal LA, 17.6 ± 7.2 mmHg in mildly dilated LA, 22.6 ± 6.3 mmHg in moderately and 22 ± 7.6 in severely dilated LA (p < 0.001). In multiple logistic regression, after adjustment for echocardiographic and clinical variables, severe LA enlargement was independently predictive of elevated PCWP (OR 3.468; 95% CI 1.046-11.504; p = 0.042). After excluding significant mitral regurgitation, progressive LA dilatation was associated with higher PCWP V-wave amplitude: from 21.3 ± 10.4 mmHg in patients with normal LA size, to 30.9 ± 11.7 mmHg in moderately dilated and 31.0 ± 11.6 mmHg in severely dilated LA (p < 0.001).

CONCLUSIONS

In patients with HF and WHO Group II PH, progressive LA enlargement was independently associated with elevated PCWP. After excluding significant mitral regurgitation, LA enlargement was also associated with increased V-wave amplitude, indicative of decreased atrial compliance.