The long-term effect of surgical aortic valve replacement on arterial stiffness and wave reflections

Background

Assessing arterial properties in patients with aortic valve stenosis undergoing surgical aortic valve replacement (SAVR) is difficult, and the results to date have been inconclusive.

Purpose

We sought to investigate how SAVR affects vascular stiffness in the short and long term.

Methods

We included 69 patients (mean age 70.8±8.4 years, 62% men) with severe symptomatic aortic stenosis who underwent SAVR. Arterial stiffness was assessed using the carotid femoral pulse wave velocity (cfPWV) and brachial-ankle pulse wave velocity (baPWV). Measurements in patients with an ankle-brachial index (ABI) <0.9 were excluded from the analysis for baPWV measurments because a low ABI can affect the accuracy of baPWV. Augmentation index corrected for heart rate (Alx@75), central pressures and subendocardial viability ratio (SEVR) were assessed with arterial tonometry. Measurements were conducted at baseline, in the acute phase and 1 year after the operation.

Results

Immediately after SAVR there was an increase in cfPWV (8.04±1.3 m/s vs 8.54±1.6 m/s, p=0.02) that was sustained at 1 year (8.04±1.3 m/s vs 9.42±2.4 m/s, p≤0.001). Similarly, baPWV (n=55) increased in the acute phase (1633±429 cm/s vs 2014±606 cm/s, p<0.001) and persisted 1 year postoperatively (1633±429 cm/s vs 1867±408 cm/s, p<0.001). Post-SAVR we also observed a decrease in Alx@75 (31.02±10% vs 22.73±12%, p≤0.001) that was attenuated 1 year later (31.02±10% vs 26.65±8%, p≤0.001), and an increase in SEVR (136.1±30.4% vs 149.2±37.7%, p=0.01) which remained improved at 1 year (136.1±30.4% vs 147.5±30.4%, p=0.01).

Conclusions

After SAVR the arterial system shows an increase of stiffness in response to the acute relief of the obstruction, which is retained in the long term.

Funding Acknowledgement

Type of funding sources: None.

Does minimal invasive cardiac surgery reduce the incidence of post-operative atrial fibrillation?

Atrial fibrillation (AF) is the most common post-operative complication and tends to be the most common arrhythmia after cardiac surgery. The etiology and risk factors for post-operative AF are poorly understood, but older age, large left atrium, diffuse coronary artery disease, a history of AF paroxysms and in general, pre-existing cardiac conditions that cause restricting and susceptibility towards inflammation have been consistently linked with post-operative atrial fibrillation (POAF). It has been traditionally thought that post-operative AF is transient, well-tolerated, benign to the patient and self-limiting complication of cardiac surgery that was temporary and easily treated. However, recent evidence suggests that POAF may be more "malignant" than previously thought, associated with follow-up mortality and morbidity. Several minimally invasive approaches, including the right parasternal approach, upper and lower mini-sternotomy (MS), V-shaped, Z-shaped, inverse-T, J-, reverse-C and reverse-L partial MS, transverse sternotomy and right mini-thoracotomy, have been developed for cardiac surgery operations since 1993 and have been associated with better outcomes and lower perioperative morbidity compared to full sternotomy (FS). The common goal of several minimally invasive approaches is to reduce invasiveness and surgical trauma. According to a statement from the American Heart Association (AHA), the term "minimally invasive" refers to a small chest wall incision that does not include a FS. This review is aimed to evaluate the use of minimally invasive techniques like mini-sternotomy, mini-thoracotomy and hybrid techniques versus conventional techniques which are used in cardiac surgery and to compare the frequency of post-operative AF and its effect on post-operative complications, morbidity and mortality, after cardiac surgery operations with FS versus cardiac surgery operations with the use of minimally invasive techniques.