Short-term effects of transcatheter aortic valve implantation on left atrial appendage function

Transcatheter aortic valve replacement in the setting of left atrial appendage thrombus

OBJECTIVES

Left atrial appendage thrombus (LAT) was an exclusion criterion in the seminal transcatheter aortic valve replacement (TAVR) trials; however, such patients do undergo TAVR in the 'real-world' setting. This study sought to analyse outcomes after TAVR in patients with LAT or spontaneous echo contrast (SEC).

METHODS

All patients undergoing TAVR at our institution between March 2009 and December 2014 were prospectively analysed. The presence of LAT or SEC was determined via a retrospective chart review. Primary outcomes included 30-day and 1-year neurological events as well as mortality.

RESULTS

Of the 369 patients undergoing TAVR, 3.8% (14) were found to have LAT and 6.8% (25) were found to have SEC, and they were separately compared to patients who did not have LAT or SEC. Significant differences were noted between groups with regard to preoperative renal function, atrial fibrillation and ejection fraction. Preoperative atrial fibrillation was the only independent predictor of LAT. No perioperative complications were associated with the presence of LAT or SEC. Specifically, no patient with LAT or SEC experienced a postoperative neurological event. While neither LAT nor SEC was an independent predictor of 30-day mortality, LAT was an independent predictor of 1-year mortality (odds ratio 3.573, 95% confidence interval 1.040-12.28; P = 0.042).

CONCLUSIONS

The current study suggests that TAVR may be performed in patients with LAT and SEC with a low risk of embolic complications. While neither was an independent predictor of 30-day mortality, LAT was an independent predictor of 1-year mortality. Larger studies are needed to better study this phenomenon.

Characterization of biventricular alterations in myocardial (reverse) remodelling in aortic banding-induced chronic pressure overload

Aortic Stenosis (AS) is the most frequent valvulopathy in the western world. Traditionally aortic valve replacement (AVR) has been recommended immediately after the onset of heart failure (HF) symptoms. However, recent evidence suggests that AVR outcome can be improved if performed earlier. After AVR, the process of left ventricle (LV) reverse remodelling (RR) is variable and frequently incomplete. In this study, we aimed at detecting mechanism underlying the process of LV RR regarding myocardial structural, functional and molecular changes before the onset of HF symptoms. Wistar-Han rats were subjected to 7-weeks of ascending aortic-banding followed by a 2-week period of debanding to resemble AS-induced LV remodelling and the early events of AVR-induced RR, respectively. This resulted in 3 groups: Sham (n = 10), Banding (Ba, n = 15) and Debanding (Deb, n = 10). Concentric hypertrophy and diastolic dysfunction (DD) were patent in the Ba group. Aortic-debanding induced RR, which promoted LV functional recovery, while cardiac structure did not normalise. Cardiac parameters of RV dysfunction, assessed by echocardiography and at the cardiomyocyte level prevailed altered after debanding. After debanding, these alterations were accompanied by persistent changes in pathways associated to myocardial hypertrophy, fibrosis and LV inflammation. Aortic banding induced pulmonary arterial wall thickness to increase and correlates negatively with effort intolerance and positively with E/e′ and left atrial area. We described dysregulated pathways in LV and RV remodelling and RR after AVR. Importantly we showed important RV-side effects of aortic constriction, highlighting the impact that LV-reverse remodelling has on both ventricles.

Conduction Abnormalities after Transcatheter Aortic Valve Implantation and Diastolic Dysfunction

OBJECTIVES

Transcatheter aortic valve implantation (TAVI) is frequently associated with the development of conduction abnormalities. We assessed the effect of conduction abnormalities on diastolic function following TAVI.

METHODS

In total, 101 consecutive post-TAVI patients were included, each with echocardiographic follow-up at 1 and 6 months. Diastolic properties were correlated with the occurrence of a long PR interval and wide QRS, and their change from baseline. The measured diastolic parameters included E/A ratio, E wave deceleration time, E wave to e' ratio, left atrial (LA) volume, and systolic pulmonary artery pressure (SPAP). The clinical outcome was all-cause mortality.

RESULTS

Overall, TAVI was associated with a consistent decrease in SPAP at the 1- and 6-month follow-up. LA volumes were increased at 1 month post-TAVI in patients with a wide compared to normal QRS (p = 0.03) and at 6 months in patients with a normal compared to prolonged PR (p = 0.03). PR prolongation above 40 ms was associated with lower SPAP at the 1- but not 6-month follow-up. Survival was not influenced by conduction abnormalities.

CONCLUSIONS

TAVI is associated with a reduction in SPAP. A postprocedural wide QRS and normal PR interval may unfavorably influence the left-sided filling performance, resulting in an increased LA volume. Other diastolic parameters, as well as survival, are not significantly affected by postprocedural conduction abnormalities.

Impact of transcatheter aortic valve implantation on left atrial appendage flow velocities

PURPOSE

Left atrial appendage (LAA) flow velocity has not been extensively studied in patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve implantation (TAVI). The aim of this study was to assess the impact of TAVI on LAA flow velocity.

METHODS

Medical records of consecutive TAVI recipients were reviewed retrospectively. Patients with persistent atrial fibrillation were excluded. LAA velocities were measured before and after TAVI by transesophageal echocardiography.

RESULTS

Sixty-one patients were included. Mean LAA emptying (EV) and filling (FV) flow velocity before TAVI were 33 ± 16 cm/s and 31 ± 14 cm/s, respectively. They increased to 37 ± 20 (p = 0.0036) and 33 ± 13 cm/s (p = 0.047) after TAVI in the whole population sample, but not in patients with normal flow AS. In low-flow, low-gradient (LFLG) AS patients, EV and FV increased from 36 ± 22 to 47 ± 30 cm/s (p < 0.01), and from 29 ± 12 to 40 ± 15 cm/s (p < 0.01), respectively, after TAVI. There was no difference between normal flow and LFLG AS patients in the number of patients who achieved EV ≥ 40 cm/s post-TAVI (35% versus 47%, p = 0.54, respectively).

CONCLUSIONS

LAA EV and FV were low prior to TAVI and increased significantly after TAVI only in patients with LFLG AS. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 44:375-382, 2016.