Frailty and transcatheter valve intervention: A narrative review.

Frailty is a common clinical syndrome that portends poor peri-procedural outcomes and increased mortality following transcatheter valve interventions. We reviewed frailty assessment tools in transcatheter intervention cohorts to recommend a pathway for preprocedural frailty assessment in patients referred for transcatheter valve procedures, and evaluated current evidence for frailty interventions and their efficacy in transcatheter intervention. We recommend the use of a frailty screening instrument to identify patients as frail, with subsequent referral for comprehensive geriatric assessment in these patients, to assist in selecting appropriate patients and then optimizing them for transcatheter valve interventions. Interventions to reduce preprocedural frailty are not well defined, however, data from limited cohort studies support exercise-based interventions to increase functional capacity and reduce frailty in parallel with preprocedural medical optimization.

Interpretation of the central aortic pressure waveform in elderly patients with aortic stenosis.

The central aortic pressure waveform, while simple in form, is complex in its physiological interpretation. Although general agreement has been reached on the contour and mechanisms responsible for pressure waveforms in the ascending aorta of healthy humans, in recent years there has been increasing interest in the contour of the pressure wave in elderly patients with aortic valve stenosis (AS). As aortic valve leaflets succumb to fibrosis and calcification, they increase opposition to forward flow. This results in a protracted pressure rise and manifests as the classical finding of pulsus parvus et tardus. Equally, changes to arterial properties (including elasticity and geometry) and pulse wave velocity (PWV) with age, heart failure, or hypertension can cause profound changes to the contour. Increased accessibility of methods to measure the central aortic pressure waveform, as well as the rapid uptake of transcatheter aortic valve implantation technologies, has created a renewed focus on better understanding of characteristic perturbations to the waveform in elderly patients with AS. In this review, we investigate the evolution of our understanding of the central aortic pressure waveform in varying AS disease states to highlight the importance of the physiological and biological basis for alterations in this waveform.

Transapical Transcatheter Mitral Valve Implantation in Heart Failure: Haemodynamic Challenges for a New Frontier.

Secondary mitral regurgitation (MR) and heart failure are mutually dependent. Secondary MR occurs as a consequence of heart failure in patients with impaired left ventricular (LV) function, decreasing cardiac efficiency, accelerating a decline in contractility and worsening the already dismal prognosis of these patients. Advances in transcatheter techniques have now given promise to improved survival, outcomes, and quality of life for patients with advanced heart failure and secondary MR. Although transcatheter edge-to-edge repair is well established, transapical transcatheter mitral valve implantation (TMVI) may represent a more durable solution for correction of secondary MR without the need for cardiopulmonary bypass. Correction of MR, however, is thought to acutely increase LV afterload due to the elimination of low afterload regurgitant flow. In high-risk patients, this may cause acute decompensated heart failure. Off-pump TMVI on a beating heart poses a number of unique challenges, but also the opportunity to study invasive haemodynamic indices in high-risk heart failure patients for the first time. In the following discussion, we review the acute haemodynamic changes during off-pump TMVI in patients with heart failure in order to better guide optimal patient selection and management.

Ageing, Hypertension and Aortic Valve Stenosis: A Conscious Uncoupling.

Aortic valve stenosis (AS) is no longer considered to be a disease of fixed left ventricular (LV) afterload (due to an obstructive valve), but rather, functions as a series circuit with important contributions from both the valve and ageing vasculature. Patients with AS are frequently elderly, with hypertension and a markedly remodelled aorta. The arterial component is sizable, and yet, the contribution of ventricular afterload has been difficult to determine. Arterial stiffening increases the speed of propagation of the blood pressure wave along the central arteries (estimated as the pulse wave velocity), which results in an earlier return of reflected waves. The effect is to augment blood pressure in the proximal aorta during systole, increasing the central pulse pressure and, in turn, placing even greater afterload on the heart. Elevated global LV afterload is known to have adverse consequences on LV remodelling, function and survival in patients with AS. Consequently, there is renewed focus on methods to estimate the relative contributions of local versus global changes in arterial mechanics and valvular haemodynamics in patients with AS. We present a review on existing and upcoming methods to quantify valvulo-arterial impedance and thereby global LV load in patients with AS.

Blood-Pressure-Monitoring Smartphone Applications: Ushering in a New Era of Wearable Cardiac Devices? Comment on Vischer et al. Comparability of a Blood-Pressure-Monitoring Smartphone Application with Conventional Measurements-A Pilot Study. Diagnostics 2022, 12, 749.

Systemic arterial hypertension in adults is generally defined as a systolic blood pressure (SBP) of >140 mmHg and/or a diastolic blood pressure (DBP) of >90 mmHg [...]

Evaluation of contemporary methods to determine vascular impedance.

The past decade has seen considerable growth in therapeutics and device technologies to treat patients with hypertension and other cardiovascular disease states. Uncoupling ventriculo-arterial interactions in these patients, however, is often complex and not adequately accounted for by arterial pressure or vascular resistance measurement alone. In reality, the global vascular load presented to the left ventricle (LV) includes both steady-state and pulsatile components. Whereas steady-state load is best represented by the vascular resistance, pulsatile load, which incorporates wave reflections and arterial stiffness, may oscillate during various phases of the cardiac cycle and is best determined by the vascular impedance (Z). In recent years, measurement of Z has become more readily accessible through an array of simultaneous applanation tonometry, echocardiography and cardiac magnetic resonance (CMR) techniques. In the following review, we evaluate existing and newer methods to assess Z so as to better understand the pulsatile characteristics of the human circulation in hypertension and other cardiovascular disease states.

Peri-procedural management of transcatheter mitral valve replacement in patients with heart failure.

Over the past decade, transcatheter mitral valve replacement (TMVR) technologies have evolved with the objective of improving outcomes for patients with severe mitral regurgitation (MR) deemed unsuitable for conventional mitral valve surgery. Although the safety and efficacy of transcatheter edge-to-edge mitral valve repair (TEER) is well-established, there is a sense amongst innovators that a major advantage of TMVR may be to offer a more complete solution for the correction of MR in patients whose complex anatomy means that the likelihood of achieving grade 0 or 1 MR with TEER is low. However, abrupt correction of MR in a poorly prepared left ventricle poses a number of unique haemodynamic challenges, particularly when sudden elimination of regurgitant flow causes a relative increase in left ventricular (LV) afterload. Rapid reduction in LV cavity size following MR elimination may itself result in relative LV outflow tract obstruction (LVOTO), irrespective of the intrinsic risk of LVOTO associated with TMVR. Nevertheless, TMVR on a beating heart affords the opportunity to study real-time invasive cardiac indices in high-risk patients with acute reversal of severe MR.

Key Echocardiographic Considerations for Tricuspid Valve Transcatheter Edge-to-Edge Repair.

Chronic tricuspid regurgitation (TR) results in progressive right ventricular (RV) volume overload, followed by right-sided chamber dilatation, RV systolic dysfunction, and eventual low-output cardiac failure. Severe TR is associated with considerable morbidity and mortality, and yet until recently, patients in the late stage of their disease course had limited treatment options. Cognizant of the high mortality rates associated with surgical intervention, tricuspid valve (TV) transcatheter edge-to-edge repair (TEER) has emerged as a promising solution for patients with severe TR. As has been learned from the transcatheter mitral valve TEER experience, detailed morphological and mechanistic assessment of the TV with transthoracic and transesophageal imaging is essential to optimal patient selection and procedural success. The current review will provide a comprehensive overview of TV anatomy, the updated mechanistic classification of TR, and key echocardiographic considerations in the evaluation, management, and follow-up of patients undergoing TV TEER.

Thirty-day and one-year outcomes following transcatheter mitral valve edge-to-edge repair versus transapical mitral valve replacement in patients with left ventricular dysfunction.

Background: A comparison of 30-day and 1-year clinical outcomes in patients with pre-existing left ventricular (LV) dysfunction undergoing transcatheter mitral valve edge-to-edge repair (TEER) or transcatheter transapical mitral valve replacement (TMVR) has not previously been reported. Aims: We aimed to compare 30-day and 1-year rates of all-cause and cardiovascular mortality as well as rehospitalisation for heart failure (HFH). Methods: All patients with severe (≥3+) symptomatic mitral regurgitation (MR) and an LV ejection fraction ≤50% who underwent TEER or TMVR over a 5-year period were evaluated. Results: Ninety-six patients (50 TEER, age 80±9 years, 70% secondary MR and 46 TMVR, age 72±9 years, 91% secondary MR) were studied. Baseline demographic and transthoracic echocardiogram characteristics were well-matched, with the exception of age (TEER 80±9 vs TMVR 72±9; p=0.01). Successful device implantation occurred in 96% of TEER patients and 97.8% of TMVR patients. Ninety-two percent of TEER patients had ≤2+MR predischarge, whilst no TMVR patient had ≥1+MR (p<0.01). No significant difference in the combined endpoint of 30-day all-cause mortality or HFH was observed (p>0.05). At 1 year, freedom from all-cause mortality and HFH was 79.2% across the entire study population but was significantly higher in patients undergoing TEER (TEER: n=45 [90%] hazard ratio 11.26, 95% confidence interval [CI]: 10.59-11.93 vs TMVR: n=39 [67.4%] 95% CI: 10.09-11.33; p=0.008). Conclusions: Despite comparable rates of successful device implantation, MR reduction, and 30-day all-cause mortality/HFH, TEER patients had lower all-cause mortality and HFH rates at 1 year.

Pre-operative pulmonary artery pulsatility index does not predict mortality post-cardiac transplantation.

AIMS: The pulmonary artery pulsatility index (PAPi) is a novel haemodynamic marker that has previously been shown to predict right ventricular dysfunction and mortality in patients with pulmonary hypertension and advanced heart failure. Utility of the PAPi in predicting outcomes post-cardiac transplantation is unknown. The aim of this study was to compare the prognostic significance of PAPi against pulmonary vascular resistance (PVR) for the predication of morbidity and all-cause mortality post-transplantation. METHODS AND RESULTS: All patients who underwent cardiac transplantation over a 6 year period were studied. Pre-operative right heart catheter data was obtained. The PAPi was calculated as follows: (systolic pulmonary artery pressure [sPAP] - diastolic pulmonary artery pressure [dPAP])/right atrial (RA) pressure. One hundred fifty-eight patients with a mean age of 49 ± 14 years were studied (43 with a pre-transplant left ventricular assist device [LVAD]). Three patients were excluded due to missing data. In the non-LVAD group, there was no significant difference in PAPi or PVR, nor was there any association with post-operative outcome (including stratification by natural history sub-type; all P > 0.05). In the LVAD group, there was no association with PAPi and post-operative outcome; however, PVR was predictive of post-operative mortality (mortality: 2.8 ± 1.3 WU vs. alive: 1.7 ± 0.7 WU; P = 0.005). CONCLUSIONS: The PAPi was not able to discriminate mortality outcomes for patients post-cardiac transplantation. Pulmonary vascular resistance remains a marker of mortality in an LVAD cohort bridged to transplant (central illustration).

ST Elevation Myocardial Infarction Complicated by Cardiogenic Shock: Systematic Review of Survival Predictors.

Background: Cardiogenic shock complicating acute myocardial infarction is associated with reduced survival despite advancements in the treatment of acute coronary syndromes. Characterizing predictors of morbidity and mortality in this setting is crucial to improving risk stratification and management. Notwithstanding, the interplay of factors determining survival in this condition remains poorly studied. Methods: Embase, MEDLINE, and CINAHL databases were searched for original studies evaluating predictors of short-term (30-day or in-hospital) survival in ST elevation myocardial infarction with cardiogenic shock (STEMI-CS). Included studies were analyzed by way of vote counting, identifying variables that predicted mortality or survival. Results: Twenty-four studies, consisting of 14,735 patients (5649 nonsurvivors and 9086 survivors) were included. All studies were observational by design (17 retrospective and 7 prospective) with clinical and statistical heterogeneity. Unsuccessful revascularization, reduced left ventricular ejection fraction, renal impairment, and other variables were identified as key independent predictors of mortality. Conclusion: Several key variables have been shown to independently increase mortality in STEMI-CS populations. Future prospective studies examining the prognostic role of multivariate scoring systems incorporating these domains are required.

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.

Prognostic role of pulmonary impedance estimation to predict right ventricular dysfunction in pulmonary hypertension.

BACKGROUND: The effect of pulmonary hypertension (PH) on right ventricular (RV) afterload is commonly defined by elevation of pulmonary artery (PA) pressure or pulmonary vascular resistance (PVR). In humans however, one-third to half of the hydraulic power in the PA is contained in pulsatile components of flow. Pulmonary impedance (Zc) expresses opposition of the PA to pulsatile blood flow. We evaluate pulmonary Zc relationships according to PH classification using a cardiac magnetic resonance (CMR)/right heart catheterization (RHC) method. METHODS: Prospective study of 70 clinically indicated patients referred for same-day CMR and RHC [60 ± 16 years; 77% females, 16 mPAP <25 mmHg (PVR <240 dynes.s.cm-5 /mPCWP <15 mmHg), 24 pre-capillary (PrecPH), 15 isolated post-capillary (IpcPH), 15 combined pre-capillary/post-capillary (CpcPH)]. CMR provided assessment of PA flow, and RHC, central PA pressure. Pulmonary Zc was expressed as the relationship of PA pressure to flow in the frequency domain (dynes.s.cm-5 ). RESULTS: Baseline demographic characteristics were well matched. There was a significant difference in mPAP (P < 0.001), PVR (P = 0.001), and pulmonary Zc between mPAP<25 mmHg patients and those with PH (mPAP <25 mmHg: 47 ± 19 dynes.s.cm-5 ; PrecPH 86 ± 20 dynes.s.cm-5 ; IpcPH 66 ± 30 dynes.s.cm-5 ; CpcPH 86 ± 39 dynes.s.cm-5 ; P = 0.05). For all patients with PH, elevated mPAP was found to be associated with raised PVR (P < 0.001) but not with pulmonary Zc (P = 0.87), except for those with PrecPH (P < 0.001). Elevated pulmonary Zc was associated with reduced RVSWI, RVEF, and CO (all P < 0.05), whereas PVR and mPAP were not. CONCLUSIONS: Raised pulmonary Zc was independent of elevated mPAP in patients with PH and more strongly predictive of maladaptive RV remodelling than PVR and mPAP. Use of this straightforward method to determine pulmonary Zc may help to better characterize pulsatile components of RV afterload in patients with PH than mPAP or PVR alone.

Characteristic changes to pulsatile and steady-state load according to pulmonary hypertension classification.

It is of increasing importance to understand and predict changes to the systemic and pulmonary circulations in pulmonary hypertension (PH). To do so, it is necessary to describe the circulation in complete quantitative terms. Characteristic impedance (Zc) expresses opposition of the circulation to pulsatile blood flow. Evaluation of systemic and pulmonary Zc relationships according to PH classification has not previously been described. Prospective study of 40 clinically indicated patients referred for CMR and RHC (56 ± 18 years; 70% females, eight mPAP ≤ 25 mmHg, 16 pre-capillary [Pre-cPH], eight combined pre- and post-capillary [Cpc-PH] and eight isolated left-heart disease [Ipc-PH]). CMR provided assessment of ascending aortic (Ao) and pulmonary arterial (PA) flow, and RHC, central Ao and PA pressure. Systemic and pulmonary Zc were expressed as the relationship of pressure to flow in the frequency domain. Baseline demographic characteristics were well-matched across PH subclasses. In those with a mPAP ≤25mHg, systemic Zc and SVR were >2 times higher than pulmonary Zc and PVR. Only Pre-cPH was associated with inverse pulsatile (systemic Zc 58 [45-69] vs pulmonary Zc 70 [58-85]), but not steady-state (SVR 1101 [986-1752] vs. PVR 483 [409-557]) relationships. Patients with CpcPH and IpcPH had concordant pulsatile and steady-state relationships (Graphical Abstract). Measurement of, and the relationship between, systemic and pulmonary Zc in patients according to PH sub-classification has not previously been described. Systemic Zc was routinely higher than pulmonary Zc, except in patients with newly diagnosed Pre-cPH, where inverse pulsatile but not steady-state relationships were observed.