Arterial Properties as Determinants of Left Ventricular Mass and Fibrosis in Severe Aortic Stenosis: Findings From ACRIN PA 4008

The Effect of Surgical Aortic Valve Replacement on Arterial Stiffness: Does the Valve Type Matter?

Background: Despite the increasing use of transcatheter aortic valve procedures, many patients still require surgical aortic valve replacement (SAVR). Assessing arterial properties in patients undergoing SAVR for aortic valve stenosis can be challenging, and the existing evidence is inconclusive. Our study aimed to investigate the impact of SAVR on vascular stiffness and the quality of life, as well as the different effects of valve type on arterial properties. Methods: We included 60 patients (mean age 70.25 ± 8.76 years, 65% men) with severe symptomatic aortic stenosis who underwent SAVR. Arterial stiffness (cfPWV, baPWV) and vascular parameters (AIx@75, central pressures, SEVR) were measured at baseline, pre-discharge, and 1-year post-operation. The QOL was assessed using the generic questionnaire-short-form health survey 36 (SF-36) pre-operatively and at 1 year. Results: Post-SAVR, cfPWV increased immediately (7.67 ± 1.70 m/s vs. 8.27 ± 1.92 m/s, p = 0.009) and persisted at 1 year (8.27 ± 1.92 m/s vs. 9.29 ± 2.59 m/s, p ≤ 0.001). Similarly, baPWV (n = 55) increased acutely (1633 ± 429 cm/s vs. 2014 ± 606 cm/s, p < 0.001) and remained elevated at 1 year (1633 ± 429 cm/s vs. 1867 ± 408 cm/s, p < 0.001). Acute decrease in Alx@75 (31.16 ± 10% vs. 22.48 ± 13%, p < 0.001) reversed at 1 year (31.16 ± 10% vs. 30.98 ± 9%, p = 0.71). SEVR improved (136.1 ± 30.4% vs. 149.2 ± 32.7%, p = 0.01) and persisted at 1 year (136.1 ± 30.4% vs. 147.5 ± 30.4%, p = 0.01). SV had a greater cfPWV increase at 1 year (p = 0.049). The QOL improved irrespective of arterial stiffness changes. Conclusions: After SAVR, arterial stiffness demonstrates a persistent increase at 1-year, with valve type having a slight influence on the outcomes. These findings remain consistent despite the perceived QOL.

Short-Term Changes in Arterial Stiffness Measured by 2D Speckle Tracking in Patients Undergoing Transcatheter Aortic Valve Implantation

Arterial stiffness has received increasing interest as a cardiovascular marker in patients with aortic valve stenosis (AS). So far, studies on the impact of aortic valve replacement (AVR) on arterial stiffness have been equivocal. Two-dimensional speckle tracking (2DST) is a novel, non-invasive method to measure the motion of the vessel wall. In this prospective observational study, we aimed to assess the change in arterial stiffness of the common carotid artery (CCA) measured by 2DST in patients undergoing transcatheter aortic valve implantation (TAVI). A total of 47 patients were included in the study (age 80.04 ± 6.065 years). Peak circumferential strain (CS) was significantly improved after TAVI (4.50 ± 2.292 vs. 5.12 ± 2.958, p = 0.012), as was the peak strain rate (CSR) (0.85 ± 0.567 vs. 1.35 ± 0.710, p = 0.002). Body mass index (BMI), mean arterial pressure (MAP) and hemodynamic parameters were associated with this change. 2DST results did not correlate with aortic pulse wave velocity (aPWV) or augmentation index normalized to heart rate (AIx@75), suggesting a distinct difference between arterial stiffness of the CCA and other stiffness parameters. 2DST seems to be a promising new tool to assess arterial stiffness in TAVI patients.

Pulsatile energy consumption as a surrogate marker for vascular afterload improves with time post transcatheter aortic valve replacement in patients with aortic stenosis

The effect of arterial stiffening on elevated pulsatile left ventricular afterload patients with aortic stenosis (AS) is pronounced beyond systemic hypertension. Circulatory afterload pulsatile efficiency (CAPE) is a marker of vascular function, defined as the ratio of steady state energy consumption (SEC) to maintain systemic circulation and pulsatile energy consumption (PEC). Twenty patients aged 80 ± 7 years were assessed at baseline and a median of 60 days post transcatheter aortic valve replacement (TAVR), with pulsatile vascular load calculated using simultaneous radial applanation tonometry derived aortic pressure and cardiac magnetic resonance phase-contrast imaging derived ascending aortic flow. Eight out of 20 patients had a reduction in PEC post TAVR, and the reduction of PEC correlated strongly with the number of days post TAVR (R = 0.62, P < 0.01). Patients assessed within the 100 days of TAVR had a rise in their PEC when compared to baseline (0.19 ± 0.09 vs 0.14 ± 0.08 W, P = 0.04). Baseline PEC correlated moderately with baseline SEC (R = 0.49, P = 0.03), and a high baseline PEC was predictive of post TAVR PEC reduction (R = 0.54, P =0.01). Overall, no significant differences were found between baseline and post TAVR for systolic aortic pressure (131 ± 20 vs 131 ± 20 mmHg), systemic vascular resistance (1894 ± 493 vs 2015 ± 519 dynes.s/cm⁵), aortic valve ejection time (337 ± 22 vs 324 ± 34 ms) or aortic characteristic impedance (120 ± 48 vs 107 ± 41 dynes.s/cm⁵). Improved flow profiles after TAVR likely unmask the true vascular properties by altering ventriculo-valvulo-arterial coupling, leading to downstream vascular remodelling secondary to flow conditioning, and results in eventual improvement of pulsatile afterload as reflected by our proposed index of CAPE.

Pathophysiology, emerging techniques for the assessment and novel treatment of aortic stenosis

Our perspectives on aortic stenosis (AS) are changing. Evolving from the traditional thought of a passive degenerative disease, developing a greater understanding of the condition's mechanistic underpinning has shifted the paradigm to an active disease process. This advancement from the 'wear and tear' model is a result of the growing economic and health burden of AS, particularly within industrialised countries, prompting further research. The pathophysiology of calcific AS (CAS) is complex, yet can be characterised similarly to that of atherosclerosis. Progressive remodelling involves lipid-protein complexes, with lipoprotein(a) being of particular interest for diagnostics and potential future treatment options.There is an unmet clinical need for asymptomatic patient management; no pharmacotherapies are proven to slow progression and intervention timing varies. Novel approaches are developing to address this through: (1) screening with circulating biomarkers; (2) development of drugs to slow disease progression and (3) early valve intervention guided by medical imaging. Existing biomarkers (troponin and brain natriuretic peptide) are non-specific, but cost-effective predictors of ventricular dysfunction. In addition, their integration with cardiovascular MRI can provide accurate risk stratification, aiding aortic valve replacement decision making. Currently, invasive intervention is the only treatment for AS. In comparison, the development of lipoprotein(a) lowering therapies could provide an alternative; slowing progression of CAS, preventing left ventricular dysfunction and reducing reliance on surgical intervention.The landscape of AS management is rapidly evolving. This review outlines current understanding of the pathophysiology of AS, its management and future perspectives for the condition's assessment and treatment.

Postprocedural ascending aortic dissection after transcatheter aortic valve implantation: a case report

Background

Transcatheter aortic valve implantation (TAVI) has been established as an effective and safe treatment for patients with severe aortic stenosis (AS). It is reported that vascular complications, especially aortic dissection, are rare. However, aortic dissection may be a serious consequence if it occurs. We experienced a case of delayed onset of ascending aortic dissection after TAVI.

Case summary

An 82-year-old woman presented with dyspnoea and general fatigue. Echocardiography revealed severe AS and she was diagnosed with heart failure associated with AS. She had difficulty controlling heart failure and required the intervention of the aortic valve. We evaluated the aortic valve and access routes with contrast-enhanced computed tomography (CT), which showed marked dilatation of the ascending aorta. Transcatheter aortic valve implantation was performed and the procedure was completed without major complications. Transoesophageal echocardiography during the procedure did not detect any obvious arterial injury. However, on the second postoperative day, the patient suddenly became unconscious and a CT indicated an ascending aortic dissection. Unfortunately, she passed away. An autopsy revealed the fragility of the ascending aorta.

Conclusion

Patients with AS and aortic root dilatation may develop delayed onset of ascending aortic dissection after TAVI.

Arterial stiffness in aortic stenosis - complex clinical and prognostic implications

Arterial stiffness and degenerative aortic stenosis (AoS) are frequently associated leading to a combined valvular and vascular load imposed on the left ventricle (LV). Vascular load consists of a pulsatile load represented by arterial stiffness and a steady load corresponding to vascular resistance. Increased vascular load in AoS has been associated with LV dysfunction and poor prognosis in pre-intervention state, as well as after aortic valve replacement (AVR), suggesting that the evaluation of arterial load in AoS may have clinical benefits. Nevertheless, studies that investigated arterial stiffness in AoS either before or after AVR used various methods of measurement and their results are conflicting. The aim of the present review was to summarize the main pathophysiological mechanisms which may explain the complex valvulo-arterial interplay in AoS and their consequences on LV structure and function on the patients' outcome. Future larger studies are needed to clarify the complex hemodynamic modifications produced by increased vascular load in AoS and its changes after AVR. Prospective evaluation is needed to confirm the prognostic value of arterial stiffness in patients with AoS. Simple, non-invasive, reliable methods which must be validated in AoS still remain to be established before implementing arterial stiffness measurement in patients with AoS in clinical practice.

Arterial Stiffness in Aortic Stenosis and the Impact of Aortic Valve Replacement

The most common cause for interventional valve treatment is aortic stenosis. A cardinal symptom of aortic stenosis is heart failure due to the increased load exerted on the left ventricle. However, the left ventricular load is not solely determined based on the degree of aortic stenosis but is also impacted by arterial stiffness. The combined load can be determined by valvulo-arterial impedance (Zva), which is associated with poor outcome in aortic stenosis. We recently demonstrated low measures of systemic arterial stiffness in patients with aortic stenosis, and that arterial stiffness was increased after surgical aortic valve replacement. The results indicated a masked arterial stiffness in aortic stenosis when using methods incorporating peripheral arterial segments. Available studies using several different methods to assess arterial stiffness in relatively small aortic stenosis cohorts examined before and after either surgical or transcatheter aortic valve replacement/intervention have generated contradictory results. In this commentary, we present a detailed literature review to explore how different methods and measures of arterial stiffness in aortic stenosis capture or not, a masked arterial stiffness in aortic stenosis and possible reasons for the observed results. Future studies validating a non-invasive reproducible method to assess arterial stiffness in aortic stenosis patients could potentially lead to an implementation in pre-interventional risk assessment for aortic stenosis.

Cardiovascular Risk Factors and Hemodynamic Measures as Determinants of Increased Arterial Stiffness Following Surgical Aortic Valve Replacement

Valvular and arterial function are tightly intertwined, both in terms of structural changes and hemodynamics. While proximal valvulo-vascular coupling contributes to the cardiovascular consequences of aortic stenosis, less is known on how peripheral arterial stiffness relates to aortic valve disease. Previous studies have shown conflicting results regarding the impact of aortic valve replacement on arterial stiffness. The aim of the present study was therefore to determine predictors of arterial stiffness in patients with and without aortic valve disease undergoing cardiac surgery. Cardio ankle vascular index (CAVI) and carotid femoral pulse wave velocity (cfPWV) were measured to determine arterial stiffness the day before and 3 days after surgery for either ascending aortic or aortic valve disease. Stratification on indication for surgery revealed that CAVI was significantly lower in patients with aortic valve stenosis (n = 45) and aortic valve regurgitation (n=30) compared with those with isolated ascending aortic dilatation (n = 13). After surgery, a significant increased CAVI was observed in aortic stenosis (median 1.34, IQR 0.74-2.26, p < 0.001) and regurgitation (median 1.04, IQR 0.01-1.49, p = 0.003) patients while cfPWV was not significantly changed. Age, diabetes, low body mass index, low pre-operative CAVI, as well as changes in ejection time were independently associated with increased CAVI after surgery. The results of the present study suggest aortic valve disease as cause of underestimation of arterial stiffness when including peripheral segments. We report cardiovascular risk factors and pinpoint the hemodynamic aspect ejection time to be associated with increased CAVI after aortic valve surgery.

Arterial biomarkers in the evaluation, management and prognosis of aortic stenosis

Degenerative aortic valve stenosis is the most common primary valve disease and a significant cause of cardiovascular morbidity and mortality. In an era when new techniques for the management of aortic stenosis are gaining ground, the understanding of this disease is more important than ever to optimize treatment. So far, the focus has been placed on the assessment of the valve itself. However, the role that the arterial system plays in the pathogenesis and natural history of the disease needs to be further elucidated. Arteriosclerosis, when it coexists with a stenotic valve, augments the load posed on the left ventricle contributing to greater impairment of cardiovascular function. Arterial stiffness, a well-established predictor for cardiovascular disease and all-cause mortality, could play a role in the prognosis and quality of life of this population. Several studies using a variety of indices to assess arterial stiffness have tried to address the potential utility of arterial function assessment in the case of aortic stenosis. Importantly, reliable data identify a prognostic role of arterial biomarkers in aortic stenosis and stress their possible use to optimize timing and method of treatment. This review aims at summarizing the existing knowledge on the interplay between the heart and the vessels in the presence of degenerative aortic stenosis, prior, upon and after interventional management. Further, it discusses the evidence supporting the potential clinical application of arterial biomarkers for the assessment of progression, severity, management and prognosis of aortic stenosis.

Non-invasive assessment of ventriculo-arterial coupling using aortic wave intensity analysis combining central blood pressure and phase-contrast cardiovascular magnetic resonance

BACKGROUND

Wave intensity analysis (WIA) in the aorta offers important clinical and mechanistic insight into ventriculo-arterial coupling, but is difficult to measure non-invasively. We performed WIA by combining standard cardiovascular magnetic resonance (CMR) flow-velocity and non-invasive central blood pressure (cBP) waveforms.

METHODS AND RESULTS

Two hundred and six healthy volunteers (age range 21-73 years, 47% male) underwent sequential phase contrast CMR (Siemens Aera 1.5 T, 1.97 × 1.77 mm2, 9.2 ms temporal resolution) and supra-systolic oscillometric cBP measurement (200 Hz). Velocity (U) and central pressure (P) waveforms were aligned using the waveform foot, and local wave speed was calculated both from the PU-loop (c) and the sum of squares method (cSS). These were compared with CMR transit time derived aortic arch pulse wave velocity (PWVtt). Associations were examined using multivariable regression. The peak intensity of the initial compression wave, backward compression wave, and forward decompression wave were 69.5 ± 28, -6.6 ± 4.2, and 6.2 ± 2.5 × 104 W/m2/cycle2, respectively; reflection index was 0.10 ± 0.06. PWVtt correlated with c or cSS (r = 0.60 and 0.68, respectively, P < 0.01 for both). Increasing age decade and female sex were independently associated with decreased forward compression wave (-8.6 and -20.7 W/m2/cycle2, respectively, P < 0.01) and greater wave reflection index (0.02 and 0.03, respectively, P < 0.001).

CONCLUSION

This novel non-invasive technique permits straightforward measurement of wave intensity at scale. Local wave speed showed good agreement with PWVtt, and correlation was stronger using the cSS than the PU-loop. Ageing and female sex were associated with poorer ventriculo-arterial coupling in healthy individuals.

Impact of Chronic Obstructive Pulmonary Disease in Heart Failure With Preserved Ejection Fraction

COPD often coexists with HFpEF, but its impact on cardiovascular structure and function in HFpEF is incompletely understood. We aimed to compare cardiovascular phenotypes in patients with Chronic Obstructive Pulmonary Disease (COPD), Heart Failure with Preserved Ejection Fraction (HFpEF), or both. We studied 159 subjects with COPD alone (n = 48), HFpEF alone (n = 79) and HFpEF + COPD (n = 32). We used MRI and arterial tonometry to assess cardiac structure and function, thoracic aortic stiffness, and measures of body composition. Relative to participants with COPD only, those with HFpEF with or without COPD exhibited a greater prevalence of female sex and obesity, whereas those with HFpEF + COPD were more often African-American. Compared to the other groups, participants with HFpEF and COPD demonstrated a more concentric LV geometry (LV wall-cavity ratio 1.2, 95%CI: 1.1-1.3; p = 0.003), a greater LV mass (67.4, 95%CI: 60.7-74.2; p = 0.03, and LV extracellular volume (49.4, 95%CI: 40.9-57.9; p = 0.002). Patients with comorbid HFpEF + COPD also exhibited greater thoracic aortic stiffness assessed by pulse-wave velocity (11.3, 95% CI: 8.7-14.0 m/s; p = 0.004) and pulsatile load imposed by the ascending aorta as measured by aortic characteristic impedance (139 dsc; 95%CI=111-166; p = 0.005). Participants with HFpEF, with or without COPD, exhibited greater abdominal and pericardial fat, without difference in thoracic skeletal muscle size. In conclusion, individuals with co-morbid HFpEF and COPD have a greater degree of systemic large artery stiffening, LV remodeling, and LV fibrosis than those with either condition alone.

Prognostic impact of arterial stiffness following transcatheter aortic valve replacement

BACKGROUND

Increased left ventricular (LV) afterload in patients with aortic stenosis consists of valvular and vascular loads; however, the effects of vascular load induced by arterial stiffness on clinical outcomes after transcatheter aortic valve replacement (TAVR) remain unclear. This study evaluated the prognostic value of brachial-ankle pulse wave velocity (baPWV) after TAVR.

METHODS

A retrospective study including 161 consecutive patients who underwent TAVR with a pre-procedural baPWV assessment was conducted. We investigated the association between baPWV and the 1-year composite outcome comprising all-cause death and rehospitalization related to heart failure. Echocardiographic measurements including the LV mass index (LVMi) and LV diastolic function at 1, 6, and 12 months after TAVR were assessed.

RESULTS

Of the 161 patients, 31 patients experienced composite outcome within 1 year after TAVR. The receiver operating characteristic curve analysis revealed that the discriminating baPWV level to discern 1-year composite outcome was 1,639 cm/s, and all subjects were allocated to two groups based on the result. Baseline characteristics were comparable between the high baPWV (n = 72) and low baPWV groups (n = 89). The Kaplan-Meier curve revealed a significantly higher cumulative 1-year composite outcome in the high baPWV group than in the low baPWV group (31% vs. 10%; log-rank test, p<0.001). High baPWV was an independent predictor of the 1-year composite outcome (adjusted hazard ratio, 3.42; 95% confidence interval, 1.62-7.85; p = 0.002). Furthermore, post-procedural echocardiography revealed that the high baPWV group had less LVMi regression and higher E/e' after TAVR compared to the low baPWV group. The delayed reversal in LVMi and diastolic function attributable to arterial stiffness might be linked to impaired clinical outcomes after TAVR.

CONCLUSIONS

Higher baPWV could be associated with adverse clinical outcomes and delayed reverse LV remodeling after TAVR.

The impact of transcatheter aortic valve implantation on arterial stiffness and wave reflections

BACKGROUND

The study of arterial properties in patients with aortic valve stenosis who undergo transcatheter aortic valve implantation (TAVI) remains challenging and results so far seem equivocal. We sought to investigate the acute and long-term effect of TAVI on arterial stiffness and wave reflections.

METHODS

We enrolled 90 patients (mean age 80.2 ± 8.1 years, 50% males) with severe symptomatic aortic stenosis undergoing TAVI. Arterial stiffness was assessed by carotid-femoral and brachial-ankle pulse wave velocity (cfPWV and baPWV). Augmentation index corrected for heart rate (AIx@75), central pressures and subendocardial viability ratio (SEVR) were assessed with arterial tonometry. Measurements were conducted at baseline, after TAVI and at 1 year.

RESULTS

Immediately after TAVI there was an increase in arterial stiffness (7.5 ± 1.5 m/s vs 8.4 ± 1.7 m/s, p = .001 for cfPWV and 1773 ± 459 vs 2383 ± 645 cm/s, p < .001 for baPWV) that was retained at 1 year (7.5 ± 1.5 m/s vs 8.7 ± 1.7 m/s, p < .001 and 1773 ± 459 cm/s vs 2286 ± 575, p < .001). Post-TAVI we also observed a decrease in AIx@75 (32.2 ± 12.9% vs 27.9 ± 8.4%, p = .016) that was attenuated 1 year later (32.2 ± 12.9% vs 29.8 ± 9.1%, p = .38), and an increase in SEVR (131.2 ± 30.0% vs 148.4 ± 36.1%, p = .002), which remained improved at 1 year (131.2 ± 30.0% vs 146.0 ± 32.2%, p = .01).

CONCLUSIONS

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

Large-Artery Stiffness in Health and Disease: JACC State-of-the-Art Review

A healthy aorta exerts a powerful cushioning function, which limits arterial pulsatility and protects the microvasculature from potentially harmful fluctuations in pressure and blood flow. Large-artery (aortic) stiffening, which occurs with aging and various pathologic states, impairs this cushioning function, and has important consequences on cardiovascular health, including isolated systolic hypertension, excessive penetration of pulsatile energy into the microvasculature of target organs that operate at low vascular resistance, and abnormal ventricular-arterial interactions that promote left ventricular remodeling, dysfunction, and failure. Large-artery stiffness independently predicts cardiovascular risk and represents a high-priority therapeutic target to ameliorate the global burden of cardiovascular disease. This paper provides an overview of key physiologic and biophysical principles related to arterial stiffness, the impact of aortic stiffening on target organs, noninvasive methods for the measurement of arterial stiffness, mechanisms leading to aortic stiffening, therapeutic approaches to reduce it, and clinical applications of arterial stiffness measurements.