Aortic regurgitation following transcatheter aortic valve replacement: Impact of preprocedural left ventricular diastolic filling patterns on late clinical outcomes

Paravalvular regurgitation after transcatheter aortic valve replacement: incidence, quantification, and prognostic impact

Transcatheter aortic valve replacement (TAVR) is the standard of care in aortic stenosis with results comparable to surgical aortic valve replacement. However, paravalvular regurgitation (PVR) is more common after TAVR. With the alteration of devices and implantation techniques, the incidence of moderate or more PVR has declined. Mild PVR is still common in around 30% of TAVR patients in low-risk trials. Progression of AS causes myocardial hypertrophy and varying degrees of diastolic dysfunction which may cause heart failure even in combination with small volumes of PVR. Any degree of PVR is associated with an increased risk of overall and cardiovascular mortality. Predictors of PVR are annular eccentricity, severe calcification of the aortic valve, bicuspid aortic valves, and type of prosthesis where balloon-expandable devices are associated with less PVR. PVR is diagnosed using echocardiography, aortic angiogram with or without videodensitometry, haemodynamic parameters, or cardiac magnetic resonance. PVR can be treated using post-dilation, interventional treatment using a vascular plug, or implantation of a second device. Successful post-dilation depends on balloon size which should at least be equal to or >95% of the mean annulus diameter. Implantation of a second device to reduce PVR is successful in ∼90% of cases, either through lengthening of the sealing skirt in case of inadequate position or through further expansion of the index device. Implantation of a vascular plug can successfully reduce PVR and reduce mortality.

Left ventricular filling pressure and survival following aortic valve replacement for severe aortic stenosis

OBJECTIVE

To determine whether echocardiography-derived left ventricular filling pressure influences survival in patients with severe aortic stenosis (AS) undergoing aortic valve replacement (AVR).

METHODS

We retrospectively reviewed 1383 consecutive patients with severe AS, normal ejection fraction and interpretable filling pressure undergoing AVR. Left ventricular filling pressure was determined according to current guidelines using mitral inflow, mitral annular tissue Doppler, estimated right ventricular systolic pressure and left atrial volume index. Cox proportional hazards regression was used to assess the influence of various parameters on mortality.

RESULTS

Age was 75±10 years and 552 (40%) were female. Left ventricular filling pressure was normal in 325 (23%), indeterminate in 463 (33%) and increased in 595 (43%). Mean follow-up was 7.3±3.7 years, and mortality was 1.2%, 4.2% and 18.9% at 30 days and 1 and 5 years, respectively. Compared with patients with normal filling pressure, patients with increased filling pressure were older (78±9 vs 70±12, p<0.001), more often female (45% vs 35%, p=0.002) and were more likely to have New York Heart Association class III-IV symptoms (35% vs 24%, p=0.004), coronary artery disease (55% vs 42%, p<0.001) and concentric left ventricular hypertrophy (63% vs 37%, p<0.001). After correction for other factors, increased left ventricular filling pressure remained an independent predictor of mortality after successful AVR (adjusted HR 1.45 (95% CI 1.16 to 1.81), p=0.005).

CONCLUSIONS

Preoperative increased left ventricular filling pressure is common in patients with AS undergoing AVR and has important prognostic implications, regardless of symptom status. Future prospective studies should consider whether patients with increased filling pressure would benefit from earlier operation.

Baseline left ventricular diastolic dysfunction affects midterm mortality after transcatheter aortic valve implantation

OBJECTIVES

To determine whether preprocedural left ventricular (LV) diastolic dysfunction impairs midterm mortality after transcatheter aortic valve implantation (TAVI) for patients with severe aortic stenosis (AS), we performed a meta-analysis of currently available evidence.

METHODS

We identified all studies investigating impact of preprocedural severity of LV diastolic dysfunction on midterm (≥1-year) all-cause mortality after TAVI for patients with AS through a search of databases (MEDLINE and EMBASE) until September 2019. From each study, we extracted an adjusted (if unavailable, unadjusted) hazard ratio (HR) of midterm mortality. We pooled study-specific estimates in the random-effects model.

RESULTS

Ten eligible studies with a total of 2380 patients with AS undergoing TAVI were identified. In accordance with pooled analyses, higher-grade preprocedural LV diastolic dysfunction was associated with significantly worse midterm all-cause mortality after TAVI compared to lower-grade dysfunction (HR for grade II vs I, 1.15; P = .002; HR for grade III vs I, 1.35; P = .001; HR for grade III vs II; 1.16, P = .002; HR for grade II-III vs I, II-III vs 0-I, or III vs I-II, 1.34; P < .00001 [primary meta-analysis]; HR per grade, 1.16; P = .003). No funnel plot asymmetry for the primary meta-analysis (for grade II-III vs I, II-III vs 0-I, or III vs I-II) was identified, which probably indicated no publication bias (P = .381 by the linear-regression test).

CONCLUSION

Higher-grade preprocedural LV diastolic dysfunction was associated with worse midterm all-cause mortality after TAVI for patients with AS compared to lower-grade dysfunction.

Left Ventricular Diastolic Dysfunction and Transcatheter Aortic Valve Replacement Outcomes: A Review

Aortic stenosis (AS) is the most common valvular disease that can lead to increased afterload, left ventricular (LV) remodeling, and myocardial fibrosis. We reviewed the literature addressing the impact of transcatheter aortic valve replacement (TAVR) on LV remodeling and patients' outcomes by elimination of AS-related high afterload. TAVR reduces afterload and improves LV remodeling recovery. However, myocardial fibrosis may not completely reverse after the TAVR. The LV diastolic dysfunction (LVDD) induced by AS is an independent predictor of post-TAVR mortality, and mortality increases with severity of LVDD. The impact of diastolic dysfunction on patient outcomes emerges at 30 days but continues to persist during mid-term follow-up. Based on severity of the baseline LVDD, some patients may tolerate post-TAVR aortic regurgitation (AR), but even minimal post-TAVR AR in patients with severe baseline LVDD can have an additive negative impact on survival. It is crucial to consider TAVR prior to development of advanced LVDD. Appropriate device selection and deployment technique are important in improvement of TAVR outcomes via elimination of AR.

The role and clinical implications of diastolic dysfunction in aortic stenosis

Diastolic dysfunction in aortic stenosis results primarily from left ventricular hypertrophy and myocardial fibrosis due to chronically elevated left ventricular systolic pressure. Currently, diastolic dysfunction does not have an explicit clinical role in management of patients with aortic stenosis. Studies have shown that improvement in diastolic dysfunction follows left ventricular remodelling after aortic valve replacement and that it occurs gradually or incompletely. Retrospective studies suggest that advanced grades of diastolic dysfunction at baseline are associated with increased mortality and adverse events even after aortic valve replacement. Recent studies have also associated myocardial fibrosis, a hallmark of diastolic dysfunction, with worse outcomes. In addition, these results were independent of the degree of aortic stenosis or valve replacement. Indirect evidence of the role of diastolic dysfunction in aortic stenosis also comes from paradoxical low-flow, low-gradient aortic stenosis, where disproportionate left ventricular hypertrophy leads to underfilling of the left ventricle, low-flow state and is associated with worse prognosis. Lastly, a limited number of studies suggest that worse diastolic dysfunction at baseline is detrimental in patients who develop aortic regurgitation after transcatheteraortic valve replacement, due to superimposition of volume overload on a stiff left ventricle. Current major limitations in our understanding of the prognostic role of diastolic dysfunction are the lack of universally accepted classification schemes, its dependence on dynamic loading conditions and the lack of larger prospective studies.

Diastolic mitral regurgitation following transcatheter aortic valve replacement: Incidence, predictors, and association with clinical outcomes

BACKGROUND

Diastolic mitral regurgitation (DMR) results from atrioventricular conduction disturbances, acute aortic regurgitation, and/or marked elevation of left ventricular filling pressure. Generally benign, in some clinical circumstances DMR has presumed to result in hemodynamic decompensation. The aforementioned causes of DMR are frequently encountered in patients treated by transcatheter aortic valve replacement (TAVR) but its clinical significance in this setting has not been studied. We sought to investigate the incidence of DMR and its prognostic implications following TAVR.

METHODS

Baseline clinical and echocardiographic variables from a prospective TAVR registry were analyzed to determine the correlates of post-procedural DMR and its impact on late outcomes (all-cause mortality and the composite of mortality and readmission due to heart failure).

RESULTS

Of 267 patients undergoing TAVR, post-procedural DMR was present in 25 (9.3%). Independent predictors of DMR included pacemaker implantation [OR=2.7 (95%CI 1.03-6.50)], post-procedural systolic MR and aortic regurgitation [OR=3.7 (1.20-10.80) and OR=4.1 (1.50-10.60), respectively], and use of self-expanding bioprostheses [OR=4.9 (1.60-21.0)]. The incidence of the combined endpoint of death and/or readmission for heart failure was higher in patients with versus those without DMR (25% vs. 41%, respectively, p=0.08), although this association did not attain statistical significance on multivariable analyses. Interaction term analysis indicated a trend toward a heightened risk for the composite endpoint among patients with post-procedural aortic regurgitation (≥moderate) in whom DMR occurred (χ² 2.94, p=0.09).

CONCLUSIONS

Although DMR following TAVR is common (occurring in approximately 1 of 10 patients), it is not independently associated with an increased risk of death and/or readmission for heart failure. Therefore, DMR post TAVR is more likely a marker of cardiac dysfunction than a causative factor.