Kristoffer Russell

Background: Aortic stenosis (AS) carries a high mortality risk if left untreated. Transcatheter aortic valve implantation (TAVI) has emerged as a primary treatment modality for many patients with severe AS. Observational data suggest that renin-angiotensin system (RAS) inhibitor use following TAVI are associated with lower risk, but with divergent reported effects and limited statistical power for specific cardiovascular outcome. This study aimed to assess the association between RAS inhibitor use and clinical outcomes after TAVI. Methods: A systematic literature search was conducted in EMBASE and PubMed. Eligible studies included those reporting on RAS inhibitor use in TAVI populations. The primary outcome was all-cause mortality. Secondary outcomes included cardiovascular mortality, myocardial infarction (MI), cerebrovascular events, and heart failure (HF) hospitalization. Results: Nine observational studies including 36,015 patients were included. RAS inhibitor use was associated with lower odds of all-cause mortality (OR 0.74, 95% CI 0.70– 0.78), cardiovascular mortality (OR 0.62, 95% CI 0.55–0.72), cerebrovascular events (OR 0.59, 95% CI 0.47–0.74), and HF hospitalization (OR 0.84, 95% CI 0.77–0.92). No clear association was observed for MI (OR 0.95, 95% CI 0.59–1.53). Conclusions: RAS inhibitor use was associated with favorable clinical outcomes following TAVI. However, these findings are based on observational data, which are subject to residual confounding. Randomized controlled trials are needed to clarify the clinical utility of RAS inhibitors in this setting.

Background and aims: Conventional echocardiographic measurements like ejection fraction (EF) and global longitudinal strain (GLS) evaluate left ventricular (LV) function without considering concurrent loading conditions. A more comprehensive characterization of cardiac function and energetics can be achieved through pressure-volume analysis, but its clinical application is limited by the requirement for invasive measurements. We aimed to develop a clinically accessible, non-invasive method for pressure-volume loop analysis. Methods: We obtained simultaneous 3-dimensional echocardiograms and invasive LV pressures with micromanometer-tipped catheters during transcatheter aortic valve replacement (TAVR) for severe aortic stenosis. Volume-time traces from the echocardiograms were combined with invasive LV pressures and non-invasive pressure estimates to construct pressure-volume loops. We used echocardiograms before and after TAVR to evaluate changes in myocardial function via non-invasive pressure-volume studies. Results: In same-beat comparisons, stroke work calculated using non-invasive LV pressure estimations correlated well with stroke work calculated using invasive LV pressures ( r = 0.95, ICC = 0.95, p < 0.0001, y = 0.90X + 1,836, mean bias −549 mmHg*mL, standard deviation 774 mmHg*mL; 95% limits of agreement: −2,006 to +967 mmHg*mL). After TAVR, stroke work fell substantially, ventricular efficiency increased, ventriculo-arterial coupling improved, and both total and resting energy consumption decreased. On the other hand, LV biplane EF and GLS remained unchanged. Conclusions: This study confirms the validity and clinical accessibility of non-invasive pressure-volume loop analysis in patients with aortic stenosis. The method identified and characterized changes in myocardial energetics, function, and ventriculo-arterial interaction, that are not typically detected by conventional echocardiography. These findings highlight the potential of non-invasive pressure-volume analysis in clinical and research practice.

Objectives: This study aimed to evaluate the ability of three-dimensional (3D) speckle tracking echocardiography (STE) to detect acute coronary occlusions in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS) and its potential diagnostic advantage over two-dimensional (2D) STE. Methods: Fifty-six patients with NSTE-ACS (mean age 64 ± 11 years; 80% male) underwent 2D and 3D transthoracic echocardiography prior to coronary angiography. Global longitudinal strain (GLS), global circumferential strain (GCS), and 3D ejection fraction (EF) were analyzed. Acute coronary occlusion was defined as TIMI flow 0–1 in the presumed culprit artery. Results: Acute coronary occlusion was present in 16 patients (29%). Patients with occlusion had significantly more impaired strain compared to those without: 3D GLS (−12.5 ± 2.7% vs. −15.5 ± 2.1%, p < 0.001), 2D GLS (−12.6 ± 2.8% vs. −15.6 ± 2.0%, p < 0.001), 3D GCS (−24.8 ± 4.4% vs. −27.8 ± 4.3%, p = 0.02), and 2D GCS (−18.1 ± 5.5% vs. −22.9 ± 4.7%, p = 0.002). In contrast, 3D EF did not differ significantly between groups (52.5 ± 4.7% vs. 54.7 ± 5.7%, p = 0.16). Receiver operating characteristic analysis showed that 3D and 2D GLS had the highest diagnostic performance (AUCs 0.81 and 0.78), while 3D EF had the lowest (AUC 0.61). Feasibility was lower for 3D STE (86%) than for 2D longitudinal strain (95%, p = 0.03). Conclusions: Both 3D and 2D GLS showed higher diagnostic accuracy than 3D EF in identifying acute coronary occlusion in NSTE-ACS patients. While 3D STE enables simultaneous assessment of multiple parameters, it did not offer incremental diagnostic value over 2D STE and had lower feasibility.

The non-invasive myocardial work index (MWI) has been validated in patients without aortic stenosis (AS). A thorough assessment of methodological limitations is warranted before this index can be applied to patients with AS. We simultaneously measured left ventricular pressure (LVP) by using a micromanometer-tipped catheter and obtained echocardiograms in 20 patients with severe AS. We estimated LVP curves and calculated pressure–strain loops using three different models: (i) the model validated in patients without AS; (ii) the same model, but with pressure at the aortic valve opening (AVO) adjusted to diastolic cuff pressure; and (iii) a new model based on the invasive measurements from patients with AS. Valvular events were determined by echocardiography. Peak LVP was estimated as the sum of the mean aortic transvalvular gradient and systolic cuff pressure. In same-beat comparisons between invasive and estimated LVP curves, Model 1 significantly overestimated early systolic pressure by 61 ± 5 mmHg at AVO compared with Models 2 and 3. However, the average correlation coefficients between estimated and invasive LVP traces were excellent for all models, and the overestimation had limited influence on MWI, with excellent correlation (r = 0.98, P < 0.001) and good agreement between the MWI calculated with estimated (all models) and invasive LVP. This study confirms the validity of the non-invasive MWI in patients with AS. The accuracy of estimated LVP curves improved when matching AVO to the diastolic pressure in the original model, mirroring that of the AS-specific model. This may sequentially enhance the accuracy of regional MWI assessment. Synopsis of the study design, key findings, and conclusions. Estimations and calculations based on Model 1 (red-dashed line) and Model 2 (blue-dashed line), where the pressure at AVO is adjusted to the diastolic cuff pressure and invasively measured LVP (grey line). AVC, aortic valve closure; AVO, aortic valve opening; MVC, mitral valve closure; MVO, mitral valve opening; LVP, left ventricular pressure; STE, speckle-tracking echocardiography.