Adult: Aortic Valve
Redefining “low risk”: Outcomes of surgical aortic valve replacement in low-risk patients in the transcatheter aortic valve replacement era

Read at the 100th Annual Meeting of The American Association for Thoracic Surgery: A Virtual Learning Experience, May 22-23, 2020.
https://doi.org/10.1016/j.jtcvs.2021.01.145Get rights and content

Abstract

Objectives

Guidelines suggest aortic valve replacement (AVR) for low-risk asymptomatic patients. Indications for transcatheter AVR now include low-risk patients, making it imperative to understand state-of-the-art surgical AVR (SAVR) in this population. Therefore, we compared SAVR outcomes in low-risk patients with those expected from Society of Thoracic Surgeons (STS) models and assessed their intermediate-term survival.

Methods

From January 2005 to January 2017, 3493 isolated SAVRs were performed in 3474 patients with STS predicted risk of mortality <4%. Observed operative mortality and composite major morbidity or mortality were compared with STS-expected outcomes according to calendar year of surgery. Logistic regression analysis was used to identify risk factors for these outcomes. Patients were followed for time-related mortality.

Results

With 15 observed operative deaths (0.43%) compared with 55 expected (1.6%), the observed:expected ratio was 0.27 for mortality (95% confidence interval [CI], 0.14-0.42), stroke 0.65 (95% CI, 0.41-0.89), and reoperation 0.50 (95% CI, 0.42-0.60). Major morbidity or mortality steadily declined, with probabilities of 8.6%, 6.7%, and 5.2% in 2006, 2011, and 2016, respectively, while STS-expected risk remained at approximately 12%. Mitral valve regurgitation, ventricular hypertrophy, pulmonary, renal, and hepatic failure, coronary artery disease, and earlier surgery date were residual risk factors. Survival was 98%, 91%, and 82% at 1, 5, and 9 years, respectively, superior to that predicted for the US age-race-sex–matched population.

Conclusions

STS risk models overestimate contemporary SAVR risk at a high-volume center, supporting efforts to create a more agile quality assessment program. SAVR in low-risk patients provides durable survival benefit, supporting early surgery and providing a benchmark for transcatheter AVR.

Graphical abstract

For a low-risk patient with Society of Thoracic Surgeons (STS) predicted risk of mortality (PROM) <4% undergoing a surgical aortic valve replacement (SAVR), across the spectrum of risk, the combined end point of major morbidity or mortality improved over the 11 years of the study period, while expected risk remained stable. For all deciles from 0% to 4%, observed operative mortality (red dots) was superior to STS expected outcomes. That survival in this patient group exceeded that of the reference US population (red dot-dash line) suggests that the benefit of SAVR is durable. These data support recommendations for early surgery, should be used as a benchmark for evolving transcatheter aortic valve replacement (TAVR) technologies, and support the effort to develop agile risk models that more accurately reflect variability in contemporary practice.

  1. Download : Download high-res image (156KB)
  2. Download : Download full-size image

Section snippets

Patients

From January 2005 to January 2017, 3474 adults with an STS PROM score <4% underwent 3493 isolated SAVRs at Cleveland Clinic's main campus. Mean age at surgery was 65 ± 13 years, and 1231 (35%) of the patients were female (Table 1). Mean preoperative aortic valve area was 0.77 ± 0.38 cm2 and mean preoperative gradient 47 ± 20 mm Hg. Age younger than 18 years, etiology of endocarditis, and those with concomitant cardiac procedures were exclusion criteria.

Surgical Technique

Isolated SAVR was performed using the

Overview

STS-defined morbidity, operative mortality, and combined major morbidity or mortality occurred similarly to STS-expected outcomes early in the study period, but occurred markedly less than STS-expected outcomes thereafter with the exception of stroke, which remained approximately constant. Operative mortality and morbidity were less than expected across the spectrum of risk in this low-risk population (PROM 0%-4%). There were relatively few intermediate-term reoperations. Long-term survival in

Principal Findings

For low-risk patients with STS PROM <4%, observed operative mortality and morbidity occurred substantially less often than expected (Figure 5). This held true for the lowest risk patients with STS PROM <1%, as well as for those with PROM of 3% to 4%. Over the decade of the study, major morbidity or mortality declined steadily to less than half of expected, while expected risk remained relatively constant, despite the increasing use of TAVR at our institution. Survival after SAVR was superior to

Conclusions

The current STS risk model, although effective at stratifying lower versus higher risk for SAVR, substantially overestimates actual SAVR risk in a high-volume center. Observed outcomes improved over time while expected risk remained static, supporting individual institutions' efforts to make continuous iterative improvements in practice even for “mature” operations such as SAVR. In addition, these results support the effort to develop agile risk models that more accurately reflect the

References (30)

Cited by (10)

  • The risk and reward of surgical aortic valve replacement

    2024, Journal of Thoracic and Cardiovascular Surgery
  • Commentary: Lake Wobegon guidelines reach Lake Erie

    2023, Journal of Thoracic and Cardiovascular Surgery
View all citing articles on Scopus

Funding provided by the Advanced Heart Valve Therapy Fund, the Delos M. Cosgrove M.D. Chair for Heart Disease Research, and the Donna and Ken Lewis Endowed Chair in Cardiothoracic Surgery.

Cleveland Clinic Aortic Valve Center Collaborators: Mona Kakavand, MD, A. Marc Gillinov, MD, Samir Kapadia, MD, Milind Y. Desai, MD, Daniel Burns, MD, MPhil, Patrick R. Vargo, MD, Shinya Unai, MD, Gösta B. Pettersson, MD, PhD, Aaron Weiss, MD, Haytham Elgharably, MD, Rishi Puri, MD, PhD, Grant W. Reed, MD, Zoran B. Popovic, MD, PhD, Wael Jaber, MD, Suma A. Thomas, MD, MBA, Faisal G. Bakaeen, MD, Tara Karamlou, MD, Hani Najm, MD, Brian Griffin, MD, Amar Krishnaswamy, MD, Kenneth R. McCurry, MD, L. Leonardo Rodriguez, MD, Nicholas G. Smedira, MD, MBA, Michael Zhen-Yu Tong, MD, MBA, Per Wierup, MD, PhD, and James Yun, MD.

View full text