Impact of balloon predilatation in patients with reduced versus preserved ejection fraction during transcatheter aortic valve implantation

Abstract

Background

Although there is a trend toward direct transcatheter aortic valve implantation (TAVI), still balloon predilatation is necessary in some cases, especially in patients with severe calcification. However, predilatation including rapid ventricular pacing may have adverse outcomes, especially in patients with reduced ejection factor (EF).

Objective

To evaluate the impact of predilatation on in-hospital outcomes in patients with reduced versus preserved EF underwent TAVI.

Methods

This was a prospective observational study including 110 patients (72 patients with preserved EF (≥50%) and 38 patients with reduced EF (<50%)) who underwent TAVI. The two groups were compared regarding in-hospital outcomes.

Results

Predilatation was done routinely in all 110 patients. The mean age was significantly higher in patients with preserved EF (82.76 ± 5.74 vs. 80.13 ± 6.51 years; p = 0.03). The majority (51.4%) of patients with preserved EF were females but the majority (73.7%) of those with reduced EF were males (P < 0.001). Predilatation showed no statistical difference regarding in-hospital mortality (2.6% vs. 1.4%; p = 0.29), hemodynamic instability (5.3% vs. 0.0%; p = 0.11), stroke (0% vs. 1.4%; p = 0.67), conduction defects (13.2% vs. 19.4%; p = 0.29), permanent pacemaker implantation (7.9% vs. 5.5%; p = 0.45), paravalvular leakage (5.3% vs. 2.8%; p = 0.42), vascular complications (7.9% vs. 11.1%; p = 0.43), and acute kidney injury (7.9% vs. 7%; p = 0.4) in patients with reduced versus preserved EF, respectively.

Conclusion

When balloon predilatation is inevitable during TAVI it is safe in patients with reduced as well as preserved EF with no added risk of hemodynamic instability or other outcomes.

Keywords

Transcatheter aortic valve implantation balloon predilatation reduced ejection factor

Introduction

Balloon predilatation before transcatheter aortic valve implantation (TAVI) was considered an important step. It allows delivery and optimal expansion of the prosthesis.^1,2 It can also be used for valve sizing in borderline annulus measurements.

However, with improvements in device delivery systems and increased experience, there is a trend toward direct TAVI² to avoid possible complications such as annulus rupture, hemodynamic instability, and stroke.^3,4 Furthermore, predilatation needs rapid pacing which may cause myocardial injury and hemodynamic instability which is expected to be more serious in patients with left ventricular dysfunction or coronary artery disease.^5,6 However, predilatation is inevitable in some patients especially those with severe calcification with uncrossable devices to facilitate deployment of valve.

In the present study, we aimed to evaluate the impact of predilatation on in-hospital clinical outcomes in patients with reduced versus preserved ejection fraction (EF) including hemodynamic instability, in-hospital mortality, conduction defects, permanent pacemaker implantation (PPI), arrhythmia, paravalvular leakage (PVL), stroke, vascular complications, tamponade, and acute kidney injury (AKI).

I-Patients and methods

Study design

One hundred and ten consecutive patients with severe symptomatic aortic stenosis who received transfemoral TAVI in Duisburg Heart Center, Duisburg, Germany, were prospectively enrolled in a prospective observational study. During the TAVI procedures, routine predilatation was performed for all patients. Valve type was randomly selected using a simple randomization method either balloon expandable or self-expandable valve with no cross-over between valve types in the study.

Ethics

The study was approved by the local ethical committee. EC/IRB file number (17200415) and approval date (28 February 2020). Written consent was taken from all patients.

Procedural aspects

Ejection fraction was assessed preprocedural by the Simpsons method dividing patients into patients with preserved EF (EF≥50%) and patients with reduced EF (<50%).⁷ TAVI procedures were performed under conscious sedation and local anesthesia. Cut down of the left or right femoral artery was chosen based on suitable anatomy. Balloon predilatation was done routinely in all patients using either (Edwards® balloon (Edwards Lifesciences Inc., Irvine, California) or VACS® III (OSYPKA, Germany)) during rapid ventricular pacing (RVP; 200 b/m). Valve type (SAPIEN3 or Evolut R/PRO (Medtronic Inc., Minneapolis, Minneapolis)) was randomly selected, and valve size selection was based on the annular dimensions as suggested by the manufacturers. Routine workup after the TAVI procedure included a clinical neurological examination, transthoracic echocardiography (TTE), and 12 lead electrocardiography monitoring. Additional tests if needed (e.g. multidetector computed tomography scan, and coronary angiography) were conducted when appropriate.

Outcomes analysis

The endpoints were procedural and in-hospital outcomes in patients with reduced versus preserved EF. Primary endpoints included hemodynamic instability and in-hospital mortality. Secondary outcomes include conduction defects, PPI, arrhythmia, PVL, stroke, vascular complications, tamponade, and AKI. All outcomes were defined according to Valve Academic Research Consortium-2 definitions.⁸

Statistical analysis

Statistical Package for the Social Science (version 20, IBM, Armonk, New York) was used. Continuous data were expressed as mean ± SD or median (range), and nominal data as frequency (percentage). A chi-square test was used to compare nominal data, continuous data were compared using the student’s t-test. The level of confidence was kept at 95%, the p-value was considered significant if <0.05.

Results

Baseline characteristics of enrolled patients

It was found that patients with preserved EF had significantly higher mean age (82.76 ± 5.74 vs. 80.13 ± 6.51 years; p = 0.03) and lower body surface area (1.84 ± 0.26 vs. 2.02 ± 0.32; p < 0.001) than those with reduced EF (Table 1)

Table 1.

Baseline characteristics of enrolled patients.

	Degree of EF by TTE		P-value
	≥50 (n = 72)	<50 (n = 38)	P-value
Age (years)	82.76 ± 5.74	80.13 ± 6.51	0.03
Sex			<0.001
Male	35 (48.6%)	28 (73.7%)
Female	37 (51.4%)	10 (26.3%)
Body mass index (kg/m²)	27.25 ± 4.95	28.20 ± 4.58	0.30
Body surface area (m²)	1.84 ± 0.26	2.02 ± 0.32	<0.001
Hypertension	58 (80.6%)	30 (78.9%)	0.51
Diabetes mellitus	20 (27.8%)	17 (44.7%)	0.06
Previous revascularization			0.57
CABG	3 (4.2%)	4 (10.5%)
PCI	23 (31.9%)	11 (28.9%)
CABG/PCI	1 (1.4%)	1 (2.6%)
Peripheral artery disease	7 (9.7%)	3 (7.9%)	0.52
Chest diseases			0.13
Asthma	0	1 (2.6%)
COPD	9 (12.5%)	1 (2.6%)
Lung cancer	2 (2.8%)	0
OSAS	5 (6.9%)	1 (2.6%)
NYHA class			0.48
Class-II	12 (16.7%)	4 (10.5%)
Class-III	57 (79.2%)	33 (86.8%)
Class-IV	3 (4.2%)	1 (2.6%)
Rhythm			0.21
Sinus	34 (47.2%)	15 (39.5%)
Atrial fibrillation	34 (47.2%)	18 (47.4%)
Paced	4 (5.6%)	5 (13.2%)
STS score	1.49 ± 0.65	1.34 ± 0.53	0.24
STS class			0.44
Mild	43 (59.7%)	26 (68.4%)
Intermediate	23 (31.9%)	11 (28.9%)
High	6 (8.3%)	1 (2.6%)
Conduction defect			0.38
None	57 (79.2%)	30 (78.9%)
RBBB	7 (9.7%)	2 (5.3%)
LBBB	2 (2.8%)	2 (5.3%)
Bisfacular block	2 (2.8%)	0
IVCD	0	2 (5.3%)
LBBB & AVB	1 (1.4%)	1 (2.6%)
RBBB & AVB	0	1 (2.6%)
AVBI	1 (1.4%)	0
IVCDplusAVB	1 (1.4%)	0
LAHB	1 (1.4%)	0

AVB: atrioventricular block; AVB I: atrioventricular block grade I; CABG: coronary artery bypass grafting; COPD: chronic obstructive lung disease; EF: ejection fraction; IVCD: intraventricular conduction delay; LAHB: left anterior hemiblock; LBBB: left bundle branch block; NYHA: New York Heart Association; OSAS: obstructive sleep apnea syndrome; PCI: percutaneous coronary intervention; RBBB: right bundle branch block; STS: society of thoracic surgeon. TTE: transthoracic echocardiography.

Data expressed as frequency (percentage), mean (SD). P-value was significant if <0.05.

The majority (51.4%) of those patients with preserved EF were females while the majority (73.7%) of those with reduced EF were males (p < 0.001). However, the other demographic and baseline characteristics showed no significant difference between both groups (p > 0.05; Table 1).

TTE findings of enrolled patients

It was found that the mean pressure gradient was significantly higher among those with preserved EF (45.09 ± 7.95 vs. 37.81 ± 8.79; p < 0.001). Of patients with reduced EF, around 24% had EF <30%. Other TTE findings showed no significant difference between both groups (Table 2).

Table 2.

TTE findings of enrolled patients.

	Degree of EF by TTE		P-value
	≥50 (n = 72)	<50 (n = 38)	P-value
Mean pressure gradient	45.09 ± 7.95	37.81 ± 8.79	<0.001
AVA by the continuity equation	0.73 ± 0.16	0.97 ± 1.20	0.08
Associated aortic regurge
None	25 (34.7%)	12 (31.6%)	0.62
I	39 (44.2%)	20 (52.6%)
≥II	8 (11.1%)	6 (15.7%)
Mitral regurge
None	10 (13.9%)	2 (5.3%)	0.17
I	48 (66.7%)	24 (63.1%)
≥II	14 (19.5%)	12 (31.6%)
Tricuspid regurge
None	13 (18.1%)	3 (7.9%)	0.08
I	45 (62.5%)	21 (55.3%)
≥II	14 (19.4%)	14 (36.8%)

AVA: aortic valve area; EF: ejection fraction; PG: pressure gradient; TTE: transthoracic echocardiography.

Data expressed as frequency (percentage), mean (SD). P-value was significant if <0.05.

Procedural data of enrolled patients

Both groups had insignificant differences with regard to all procedural data with exception of a significantly smaller size of balloon (22.25 ± 1.86 vs. 23.15 ± 1.84; p = 0.01) among those patients with preserved EF (Table 3).

Table 3.

Procedural data of enrolled patients.

	Degree of EF by TTE		P-value
	≥50 (n = 72)	<50 (n = 38)	P-value
Route
Right femoral	46 (63.9%)	20 (52.6%)	0.17
Left femoral	26 (36.1%)	18 (47.4%)
Type of valve
SAPIEN 3	40 (55.6%)	19 (50%)	0.36
Evolute R/ PRO	32 (44.4%)	19 (50%)
Size of balloon	22.25 ± 1.86	23.15 ± 1.84	0.01
Valve size SAPIEN 3
23	14 (19.4%)	4 (10.5%)	0.17
26	17 (23.6%)	10 (26.3%)
29	9 (12.5%)	5 (13.2%)
Evolute R/PRO
26	16 (22.2%)	3 (7.9%)
29	13 (18%)	12 (31.6%)
34	3 (4.2%)	4 (10.5%)
Aortic regurge index (%)	29.85 ± 8.07	29.13 ± 6.85	0.72
Amount of dye (ml)	138.33 ± 46.21	132.89 ± 32.10	0.51
Radiation (mG)	4945.44 ± 2401.95	4342.11 ± 3362.71	0.28
Post-dilatation	8 (11.1%)	3 (7.9%)	0.53

EF: ejection fraction; LVOT: Left ventricular outflow tract; STJ: sinotubular junction; TEE: transesophageal echocardiography.

Data expressed as frequency (percentage), mean (SD). P-value was significant if <0.05.

Outcomes and complications of enrolled patients

There was no statistically significant difference between the two groups. We noticed that only two patients with reduced EF developed hemodynamic instability after predilatation (Table 4). When we compared the subgroups of patients with reduced EF (40%–50%, 30% to <40%, and <30%) there was no statistically significant difference between subgroups except for PVL ≥ grade II at hospital discharge which was more in subgroup 30% to <40% EF (p = 0.01; Table 5).

Table 4.

Outcomes and complications of enrolled patients based on EF by TTE.

	Degree of EF by TTE		P-value
	≥50 (n = 72)	<50 (n = 38)	P-value
Immediate PVL
No/trace	45 (62.5%)	20 (52.6%)	0.21
Grade I	19 (26.4%)	12 (31.6%)
≥Grade II	8 (11.1%)	6 (15.8%)
PVL at discharge
No/trace	50 (69.4%)	25 (65.8%)	0.42
≥Grade I	20 (27.8%)	11 (28.9%)
≥Grade II	2 (2.8%)	2 (5.3%)
Prosthesis embolization	1 (1.4%)	1 (2.6%)	0.29
Bleeding	1 (1.4%)	0	0.65
Vascular site complications	8 (11.1%)	3 (7.9%)	0.43
Acute kidney injury	5 (7%)	3 (7.9%)	0.40
Stroke	1 (1.4%)	0	0.67
Need to second valve	1 (1.4%)	1 (2.6%)	0.29
Arrhythmia	1 (1.4%)	1 (2.6%))	0.29
Conduction defect	14 (19.4%)	5 (13.2%)	0.29
Pacemaker implantation	4 (5.5%)	3 (7.9%)	0.45
Hemodynamic instability after predilatation	0 (0.0%)	2 (5.3%)	0.11
Tamponade	2 (2.8%)	0	0.42
Aortic dissection	0	0
Annular rupture	0	0
Coronary occlusion	0	0
In-hospital mortality	1 (1.4%)	1 (2.6%)	0.29

EF: ejection fraction; TEE: transesophageal echocardiography.

Data expressed as frequency (percentage), mean (SD). P-value was significant if <0.05.

Table 5.

Outcomes and complications in subgroups of patients with EF<50%.

	Degree of EF by TTE			P-value
	40–50%(n = 19)	30–40%(n = 10)	<30%(n = 9)	P-value
Immediate PVL				0.34
≤Grade I	17(89.4%)	7 (70%)	8(88%)
≥Grade II	2 (10.5%)	3(30%)	1(12%)
PVL at discharge
≤Grade I	19 (100%)	8(80%)	9(100%)	0.01
≥Grade II	0 (0%)	2 (20%)	0(0%)
Prosthesis embolization	1(5.2%)	0	0	0.34
Bleeding	0	0	0
Vascular site complications	1(5.2%)	1(10%)	1(11%)	0.82
Acute kidney injury	1(5.2%)	1(10%)	1(11%)	0.82
Stroke	0	0	0	0
Need to second valve	1(5.2%)	0	0
Arrhythmia	1(5.2%)	0	0
Conduction defect	3 (10.5%)	1(10%)	1(11%)	0.67
Pacemaker implantation	2 (158%)	1(10%)	0	0.44
Hemodynamic instability after predilatation	0 (0.0%)	1(10%)	1(11%)	0.52
Tamponade	0	0	0
Aortic dissection	0	0	0
Annular rupture	0	0	0
Coronary occlusion	0	0	0
In-hospital mortality	1(5.2%)	0	0	0.59

EF: ejection fraction; TEE: transesophageal echocardiography.

Data expressed as frequency (percentage), mean (SD). P-value was significant if <0.05.

Discussion

In our study, we found that predilatation before TAVI has comparable outcomes in patients with preserved and reduced EF. To our knowledge, this study is the first study that compared the impact of balloon predilatation in patients with reduced versus preserved EF. Predilatation before TAVI has several advantages: it facilitates deliverability and optimal valve deployment, thereby reducing the risk of PVL and the need for post-dilatation which may carry the risk of device embolization or annulus rupture and may affect the long-term durability of the valve.⁹

Also, predilatation helps to predict the risk of left main (LM) coronary artery obstruction during TAVI, which results from displacement of the native valve leaflets over LM ostia.¹⁰ This can be done by assessing the interaction of the displaced leaflets with the coronary ostia during predilatation. Accordingly, the operator can decide to either abort the TAVI procedure or consider preventive measures like prophylactic guidewire engagement of the left coronary system at risk or use of a specific type of transcatheter heart valves (THV).⁹

Finally, predilatation may help to identify patients with severe focal calcifications who may be liable to complications during TAVI procedures. Condado et al.¹¹ found that the presence of calcium-related leakage during balloon sizing despite complete filling of the sinuses of Valsalva by the balloon may help to identify patients at higher risk for annular rupture and they described this as a high-risk calcification.

However, predilatation may increase the risk of stroke, annular rupture, and conduction defects with the need for pacemaker implantation which may be deleterious to patients with reduced EF.⁶ In addition, predilatation needs RVP to allow optimal balloon positioning and avoids excessive movements of the balloon during inflation.¹² However, RVP carries the risk of induction of ventricular fibrillation.¹³ It may also cause hemodynamic instability due to decreased cardiac output especially in patients with severely reduced EF due to myocardial stunning.¹⁴

Furthermore, aortic stenosis patients with preserved EF usually have left ventricular hypertrophy, impaired relaxation, and reduced left ventricular capacity which may make them vulnerable to prolonged hypotension immediately after RVP.¹⁵

Also, patients with pre-existent low flow-low gradient aortic stenosis, severe aortic regurgitation, severe left ventricular systolic dysfunction, or severe pulmonary hypertension may be at high risk of acute decompensation and hemodynamic instability after predilatation.^9,15

On the other hand, Witzke et al.¹⁴ studied the outcomes of RVP during predilatation and stated that predilatation using RVP is feasible and safe. It offers greater balloon positioning and stability during inflation without affecting the incidence of in-hospital adverse events and can be performed safely in high-risk patients including patients with reduced EF.¹⁴ In our study only two patients (5.3%) with reduced EF developed hemodynamic instability after predilatation which required rapid valve implantation.

Also, Ertugrul et al.¹⁶ found that RVP can be used effectively and safely during balloon predilatation; it decreases procedural failure rate, eases the procedure, and prevents the development of aortic regurge (AR) through the stabilization of the balloon.

In addition, Mylonas et al.¹⁷ mentioned that RVP during predilatation can be safely used to achieve balloon stability and does not increase the risk of sustained ventricular arrhythmias compared to the baseline risk of cardiac catheterization. However, none of these studies compared the outcomes of balloon predilatation in patients with reduced versus preserved EF.

Predilatation may increase the risk of embolization due to the additional manipulations, but on the other hand, balloon inflation may fragment calcific debris on the aortic valve, stabilize such debris through a homogeneous apposition onto aortic leaflets and, thereby, reduce embolization during valve implantation.¹³ In general, stroke rates are less with new generation devices, whether using predilatation or not.¹⁸ In our study, only one patient developed clinical stroke (0.9%), however, subclinical stroke was not excluded.

Theoretically, predilatation might increase the risk of damage to the conduction system by increasing itrogenic damage and trauma. However, the PPI rate in our study was only 6.4% with no significant differences between patients with reduced versus preserved EF (7.9% vs. 5.5%; p = 0.37). In addition, Bonaros et al.¹⁹ and Schymik et al.²⁰ compared TAVI with and without predilatation and noticed a similar incidence of conduction defects for both groups.

Transient hypotension during predilatation and contrast injection if predilatation is used for sizing purposes may add risk for kidney injury, especially in patients with reduced EF. Fefer et al.²¹ mentioned that predilatation involving rapid pacing and contrast injection was associated with an increased incidence of AKI in patients with reduced EF. In the current study, no significant difference was present between the two study groups (7.9% vs. 7.0%, p = 0.4; reduced vs. preserved EF groups, respectively).

Kefer et al.²² noticed that the safety of predilatation was similarly high in patients with impaired versus preserved left ventricular function, except for ventricular arrhythmias. In our study, all other outcomes were comparable in both patient groups.

Limitations

Small sample size and single-center study. We also depend on in-hospital outcomes trusting that any complication related to predilatation is reflected early during hospital admission.

Conclusion

When predilatation before TAVI is inevitable, it can be done safely in patients with reduced as well as preserved EF.

Footnotes

Authors’ contributions

Heba M. Elnaggar and Marwan S. Mahmoud contributed to the acquisition of data, analysis, and interpretation of the data, drafting of the article, and writing of the manuscript. Wolfgang Schoels contributed to the conception and design and writing of the manuscript. Heba M. Elnaggar, Matthias Kullmer, and Mohamad Dia contributed to writing and revising the manuscript. Yehia Taha Kishk and Magdy Algowhary contributed to the writing and final revision of the manuscript.

Declaration of conflicting interests

The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The authors received no financial support for the research, authorship, and/or publication of this article.

Ethical approval

Not applicable.

Informed consent

Not applicable.

ORCID iDs

Marwan S. Mahmoud

Magdy Algowhary

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