Early hemodynamic changes after transcatheter aortic valve implantation in patients with severe aortic stenosis measured by invasive pressure volume loop analysis

Temporary decrease in microvascular tissue saturation after transcatheter aortic valve implantation

BACKGROUND

Data on the effect of transcatheter aortic valve implantation (TAVI) on peripheral microcirculation are limited.

OBJECTIVE

The aim of this study is to evaluate peripheral microvascular tissue saturation (StO2) before and after TAVI in relation to central and peripheral hemodynamics, cardiac and renal function.

METHODS

In this single-center prospective study, patients with severe aortic stenosis (sAS) scheduled for TAVI or cardiac catheterization (control) were assessed before and up to five days after the procedure. Cardiac function including cardiac output (CO) was assessed by echocardiography. Brachial (bBP) and central blood pressure (cBP), ankle brachial index (ABI), and parameters of arterial stiffness, including augmentation pressure (AP) and augmentation index adjusted for heart rate (AIx@HR75) were measured to assess hemodynamic changes. StO2 was measured in all extremities using a near-infrared spectroscopy (NIRS) camera. Renal function was measured by creatinine levels.

RESULTS

26 patients underwent TAVI and 11 patients served as control. Cardiac output was significantly increased, whereas hemodynamic parameters and peripheral StO2 were significantly decreased after TAVI. At follow-up, StO2 returned to baseline values. Changes in StO2 were negatively related to creatinine levels.

CONCLUSION

Transcatheter aortic valve implantation causes a temporary decrease in microvascular tissue saturation that is associated with renal function.

Cardiac output in patients with small annuli undergoing transcatheter aortic valve implantation with self-expanding versus balloon expandable valve (COPS-TAVI)

BACKGROUND

There is limited data on cardiac output in patients with small aortic annuli undergoing trans-catheter aortic valve implantation (TAVI) according to the implanted platform of balloon-expandable (BEV) compared to self-expanding valves (SEV).

METHODS

This is a retrospective analysis of consecutive patients with severe aortic stenosis and small annuli who underwent successful TAVI. Cardiac output was measured using echocardiography within 4 weeks following TAVI. Data were recorded and analysed by an experienced operator who was not aware of the type of the implanted valve.

RESULTS

138 patients were included in the analysis, of whom 57 % underwent TAVI with BEV. Clinical and echocardiographic characteristics were comparable between the two platforms, except for more frequent previous cardiac surgery and smaller indexed aortic valve in the BEV group. There was no relationship between computed tomography-derived aortic annulus area and cardiac output post TAVI. When compared to patients who underwent TAVI with BEV, those with SEV had larger cardiac output [mean difference - 0.50 l/min, 95 % CI (-0.99, -0.01)] and cardiac index [mean difference - 0.20 l/min/m2, 95 % CI (-0.47, 0.07)], although the latter did not reach statistical significance. Unlike patients with small body surface area, in those with large body surface area both cardiac output and cardiac index were statistically larger in patients who underwent SEV compared to BEV.

CONCLUSION

Cardiac output, as measured by echocardiography, was larger in patients with small annuli who underwent TAVI procedure with SEV compared to BEV. Such difference was more evident in patients with large body surface area.

Noninvasive Hemodynamic Evaluation Following TAVI for Severe Aortic Stenosis

Background Various hemodynamic changes occur following transcatheter aortic valve implantation (TAVI) that may impact therapeutic decisions. NICaS is a noninvasive bioimpedance monitoring system aimed at hemodynamic assessment. We used the NICaS system in patients with severe aortic stenosis (AS) to evaluate short-term hemodynamic changes after TAVI. Methods and Results We performed hemodynamic analysis using NICaS on 97 patients with severe AS who underwent TAVI using either self-expandable (68%) or balloon-expandable (32%) valves. Patients were more often women (54%) and had multiple comorbidities including hypertension (83%), coronary artery disease (46%), and diabetes (37%). NICaS was performed at several time points-before TAVI, soon after TAVI, at hospital discharge, and during follow-up. Compared with baseline NICaS measurements, we observed a significant increase in systolic blood pressure and total peripheral resistance (systolic blood pressure 132±21 mm Hg at baseline versus 147±23 mm Hg after TAVI, P<0.001; total peripheral resistance 1751±512 versus 2084±762 dynes*s/cm⁵, respectively, P<0.001) concurrent with a decrease in cardiac output and stroke volume (cardiac output 4.2±1.5 versus 3.9±1.3 L/min, P=0.037; stroke volume 61.4±14.8 versus 56.2±15.9 mL, P=0.001) in the immediate post-TAVI period. At follow-up (median 59 days [interquartile range, 40.5-91]) these measurements returned to values that were not different from the baseline. A significant improvement in echocardiography-based left ventricular ejection fraction was observed from baseline to follow-up (55.6%±11.6% to 59.4%±9.4%, P<0.001). Conclusions Unique short-term adaptive hemodynamic changes were observed using NICaS in patients with AS soon after TAVI. Noninvasive hemodynamic evaluation immediately following TAVI may contribute to the understanding of complex hemodynamic changes and merits favorable consideration.

Invasive Real Time Biventricular Pressure-Volume Loops to Monitor Dynamic Changes in Cardiac Mechanoenergetics During Structural Heart Interventions: Design and Rationale of a Prospective Single-Center Study

Background

Transcatheter valvular interventions affect cardiac and hemodynamic physiology by changing ventricular (un-)loading and metabolic demand as reflected by cardiac mechanoenergetics. Real-time quantifications of these changes are scarce. Pressure-volume loop (PVL) monitoring appraises both load-dependent and load-independent compounds of cardiac physiology including myocardial work, ventricular unloading, and ventricular-vascular interactions. The primary objective is to describe changes in physiology induced by transcatheter valvular interventions using periprocedural invasive biventricular PVL monitoring. The study hypothesizes transcatheter valve interventions modify cardiac mechanoenergetics that translate into improved functional status at 1-month and 1-year follow-up.

Methods

In this single-center prospective study, invasive PVL analysis is performed in patients undergoing transcatheter aortic valve replacement or tricuspid or mitral transcatheter edge-to-edge repair. Clinical follow-up is per standard of care at 1 and 12 months. This study aims to include 75 transcatheter aortic valve replacement patients and 41 patients in both transcatheter edge-to-edge repair cohorts.

Results

The primary outcome is the periprocedural change in stroke work, potential energy, and pressure-volume area (mmHg mL^-1). The secondary outcomes comprise changes in a myriad of parameters obtained by PVL measurements, including ventricular volumes and pressures and the end-systolic elastance-effective arterial elastance ratio as a reflection of ventricular-vascular coupling. A secondary endpoint associates these periprocedural changes in cardiac mechanoenergetics with functional status at 1 month and 1 year.

Conclusions

This prospective study aims to elucidate the fundamental changes in cardiac and hemodynamic physiology during contemporary transcatheter valvular interventions.

Improvement of hemodynamic parameters in aortic stenosis patients with transcatheter valve replacement by using impedance cardiography

Background

The hemodynamic changes of patients with aortic stenosis (AS) who underwent transcatheter valve replacement (TAVR) have not been completely investigated.

Methods and results

We enrolled 74 patients with AS who underwent TAVR and assessed cardiac function changes at 1 week post-operation by impedance cardiography (ICG) in a supine position at rest for more than 15 min. Of the 74 patients, 47 had preserved left ventricular ejection fraction (LVEF ≥ 50%; preserved-LVEF group) and 27 had reduced LVEF (LVEF <50%; reduced-LVEF group). TAVR improved the cardiac structure and function, as evidenced by the decrease in the left ventricular end-diastolic (LVED), left atrial diameter (LAD), and an increase in the LVEF. We observed a decrease in N-terminal pro-brain natriuretic peptide (NT-proBNP) level compared to that before treatment. Moreover, patients with reduced LVEF had a more significant reduction of NT-proBNP than those with preserved LVEF. Meanwhile, the blood pressure of patients had no significant differences pre- and post-operation. Based on ICG, there were no changes in the parameter of cardiac preload [thoracic fluid content (TFC)]. We observed an improvement in parameters of diastolic cardiac function [left ventricular ejection time (LVET) and pre-ejection period (PEP)]. And we detected converse results in parameters of heart systolic function [systolic time ratio (STR), cardiac output (CO), cardiac index (CI), stroke index (SI), and stroke volume (SV)] and cardiac afterload [stroke systemic vascular resistance (SSVR) and SSVR-index (SSVRI)]. In addition, TFC level was decreased in patients with thoracic volume overload after valve replacement. Subgroup analysis showed that the changes in those parameters were more noticeable in patients with reduced LVEF than that with preserved LVEF. Moreover, we observed no effects on parameters of heart systolic function and heart afterload in the LVEF ≥ 50% group before and after TAVR.

Conclusion

Our data revealed a beneficial effect of TAVR in diastolic function and preload as detected by the ICG. But the LV systolic function and cardiac afterload were not improved in patients with LVEF <50%. The result indicated that ICG could be used as an important technique to monitor the cardiac condition of patients after aortic valve replacement.

Cardiac Structural Remodeling and Hemodynamic Patterns Following Transcatheter Aortic Valve Replacement

Background Transcatheter aortic valve replacement (TAVR) is increasingly utilized for most patients with symptomatic severe aortic stenosis. TAVR is linked to enhanced long-term cardiac hemodynamics, reversal of left ventricle (LV) hypertrophy, and improved aortic valve gradients. We present a retrospective observational study assessing cardiac remodeling and valvular flow patterns post-TAVR. Methods Retrospective echocardiographic data were collected, evaluating cardiac function and valvular flow patterns before and after TAVR at a single institution. Data was compiled and statistically analyzed using a paired t-test evaluating variations at approximately 30 days and one-year post-TAVR. Results On echocardiogram 30 days and one-year post-TAVR, there was a reduction in LV mass index from 132 g/m² to 110 g/m² (95%CI: 98-122; p=0.01) and 118 g/m² (95%CI: 102-133; p=0.03), and a reduction in relative wall thickness from 0.54 to 0.49 (95%CI: 0.46-0.52; p=0.05) and 0.44 (95%CI: 0.38-0.49; p=0.03), respectively. Doppler velocity indices (DVI) increased from 0.24 to 0.61 (95%CI: 0.49-0.73; p<0.001) and 0.57 (95%CI: 0.48-0.65; p<0.001). Expected improvement in aortic valve velocities and gradients were observed post-TAVR. Conclusions Following TAVR, LV remodeling can be observed as early as 30 days. This is demonstrated by a reduction in LV mass index and relative wall thickness in conjugation with an anticipated improvement in valvular flow patterns and flow across the aortic valve.