Fluid-filled versus sensor-tipped pressure guidewires for FFR and Pd/Pa measurement; PW-COMPARE study

BACKGROUND

Fluid-filled pressure guidewires are unaffected by the previously inevitable hydrostatic pressure gradient (HPG). This study aimed to compare simultaneous pressure measurements with fluid-filled and sensor-tipped pressure guidewires.

METHODS

Fifty patients underwent fractional flow reserve (FFR) and Pd/Pa measurement with a fluid-filled and a sensor-tipped pressure guidewire simultaneously. To assess maneuverability, patients were randomized with respect to which pressure guidewire was used to cross the lesion first. Lateral fluoroscopy was used to estimate height difference between catheter tip and distal wire position (and thus HPG). Agreement between pressure measurements was studied.

RESULTS

Measurements were performed in LM (4% (n = 2)), LAD (44% (n = 22)), LCX (26% (n = 13)), and RCA (26% (n = 13)). Simultaneous pressure measurements showed excellent agreement (mean FFR difference - 0.01 ± 0.03 (r = 0.959, p < 0.001), mean Pd/Pa difference - 0.01 ± 0.04 (r = 0.929, p < 0.001)). FFR was ≤0.80 in 42.6% (n = 20) with fluid-filled FFR measurements versus 46.8% (n = 22) by sensor-tipped FFR measurements. Mean height difference was 15 ± 34 mm, and strongly dependent on the coronary artery (LAD 45 ± 10 mm, LCX -23 ± 16 mm, RCA -13 ± 17 mm). There was a strong correlation between height difference and difference in pressure ratios between sensor-tipped and fluid-filled pressure guidewires (FFR r = -0.850, p < 0.001; Pd/Par = -0.641, p < 0.001). Largest FFR differences were present in the LAD (-0.04 ± 0.02). After HPG correction, mean difference between HPG-corrected sensor-tipped FFR and fluid-filled FFR was 0.00 ± 0.02, mean Pd/Pa difference was 0.01 ± 0.03.

CONCLUSIONS

This study shows excellent overall correlation between FFR and Pd/Pa measurements with both pressure guidewires. Differences measured with fluid-filled and sensor-tipped pressure guidewires are vessel-specific and attributable to hydrostatic pressure gradients (NCT04802681).

Is the Corrected Carotid Flow Time a Clinically Acceptable Surrogate Hemodynamic Parameter for the Left Ventricular Ejection Time?

OBJECTIVE

The corrected left ventricular ejection time (cLVET) comprises the phase from aortic valve opening to aortic valve closure corrected for heart rate. As a surrogate measure for cLVET, the corrected carotid flow time (ccFT) has been proposed in previous research. The aim of this study was to assess the clinical agreement between cLVET and ccFT in a dynamic clinical setting.

METHODS

Twenty-five patients with severe aortic valve stenosis (AS) were selected for transcatheter aortic valve replacement (TAVR). The cLVET and ccFT were derived from the left ventricular outflow tract (LVOT) and the common carotid artery (CCA), respectively, using pulsed wave Doppler ultrasound. Bazett's (B) and Wodey's (W) equations were used to calculate cLVET and ccFT. Measurements were performed directly before (T1) and after (T2) TAVR. Correlation, Bland-Altman and concordance analyses were performed.

RESULTS

Corrected LVET decreased from T1 to T2 (p < 0.001), with relative reductions of 11% (B) and 9% (W). Corrected carotid flow time decreased (p < 0.001), with relative reductions of 12% (B) and 10% (W). The correlation between cLVET and ccFT was strong for B (ρ = 0.74, p < 0.001) and W (ρ = 0.81, p < 0.001). The bias was -39 ms (B) and -37 ms (W), and the upper and lower levels of agreement were 19 and -98 ms (B) and 5 and -78 ms (W), respectively. Trending ability between cLVET and ccFT was good (concordance 96%) for both B and W.

CONCLUSION

In TAVR patients, the clinical agreement between cLVET and ccFT was acceptable, indicating that ccFT could serve as a surrogate measure for cLVET.

Cost-utility analysis of TAVI compared with surgery in patients with severe aortic stenosis at low risk of surgical mortality in the Netherlands

BACKGROUND

There is growing evidence to support the benefits of transcatheter aortic valve implantation (TAVI) over surgical aortic valve replacement (SAVR) in patients with symptomatic severe aortic stenosis (sSAS) who are at high- or intermediate-risk of surgical mortality. The PARTNER 3 trial showed clinical benefits with SAPIEN 3 TAVI compared with SAVR in patients at low risk of surgical mortality. Whether TAVI is also cost-effective compared with SAVR for low-risk patients in the Dutch healthcare system remains uncertain. This article presents an analysis using PARTNER 3 outcomes and costs data from the Netherlands to inform a cost-utility model and examine cost implications of TAVI over SAVR in a Dutch low-risk population.

METHODS

A two-stage cost-utility analysis was performed using a published and validated health economic model based on adverse events with both TAVI and SAVR interventions from a published randomized low risk trial dataset, and a Markov model that captured lifetime healthcare costs and patient outcomes post-intervention. The model was adapted using Netherlands-specific cost data to assess the cost-effectiveness of TAVI and SAVR. Uncertainty was addressed using deterministic and probabilistic sensitivity analyses.

RESULTS

TAVI generated 0.89 additional quality-adjusted life years (QALYs) at a €4742 increase in costs per patient compared with SAVR over a lifetime time horizon, representing an incremental cost-effectiveness ratio (ICER) of €5346 per QALY gained. Sensitivity analyses confirm robust results, with TAVI remaining cost-effective across several sensitivity analyses.

CONCLUSIONS

Based on the model results, compared with SAVR, TAVI with SAPIEN 3 appears cost-effective for the treatment of Dutch patients with sSAS who are at low risk of surgical mortality. Qualitative data suggest broader societal benefits are likely and these findings could be used to optimize appropriate intervention selection for this patient population.

Prehospital risk assessment and direct transfer to a percutaneous coronary intervention centre in suspected acute coronary syndrome

OBJECTIVE

Prehospital risk stratification and triage are currently not performed in patients suspected of non-ST-segment elevation acute coronary syndrome (NSTE-ACS). This may lead to prolonged time to revascularisation, increased duration of hospital admission and higher healthcare costs. The preHEART score (prehospital history, ECG, age, risk factors and point-of-care troponin score) can be used by emergency medical services (EMS) personnel for prehospital risk stratification and triage decisions in patients with NSTE-ACS. The aim of the current study was to evaluate the effect of prehospital risk stratification and direct transfer to a percutaneous coronary intervention (PCI) centre, based on the preHEART score, on time to final invasive diagnostics or culprit revascularisation.

METHODS

Prospective, multicentre, two-cohort study in patients with suspected NSTE-ACS. The first cohort is observational (standard care), while the second (interventional) cohort includes patients who are stratified for direct transfer to either a PCI or a non-PCI centre based on their preHEART score. Risk stratification and triage are performed by EMS personnel. The primary endpoint of the study is time from first medical contact until final invasive diagnostics or revascularisation. Secondary endpoints are time from first medical contact until intracoronary angiography (ICA), duration of hospital admission, number of invasive diagnostics, number of inter-hospital transfers and major adverse cardiac events at 7 and 30 days.

RESULTS

A total of 1069 patients were included. In the interventional cohort (n=577), time between final invasive diagnostics or revascularisation (42 (17-101) hours vs 20 (5-44) hours, p<0.001) and length of hospital admission (3 (2-5) days vs 2 (1-4) days, p=0.007) were shorter than in the observational cohort (n=492). In patients with NSTE-ACS in need for ICA or revascularisation, healthcare costs were reduced in the interventional cohort (€5599 (2978-9625) vs €4899 (2278-5947), p=0.02).

CONCLUSION

Prehospital risk stratification and direct transfer to a PCI centre, based on the preHEART score, reduces time from first medical contact to final invasive diagnostics and revascularisation, reduces duration of hospital admission and decreases healthcare costs in patients with NSTE-ACS in need for ICA or revascularisation.

TRIAL REGISTRATION

NCT05243485.

Outcomes of emergent cardiac surgery after transcatheter aortic valve implantation

OBJECTIVE

The aim of this study was to evaluate the reasons for emergent cardiac surgery (ECS) after transcatheter aortic valve implantation (TAVI) and assess outcomes of these patients.

METHODS

All patients undergoing ECS following a complicated TAVI procedure at a high-volume TAVI centre in the Netherlands from 1 January 2008 to 1 April 2022 were included. Baseline and procedural characteristics and outcome data (procedural, 30-day and 1‑year mortality, in-hospital stroke, 30-day pacemaker implantation, 30-day vascular complications, 30-day deep sternal wound infections and 30-day re-exploration) were collected from patient files and analysed using descriptive statistics.

RESULTS

During the study period, 16 of 1594 patients (1.0%) undergoing TAVI required ECS. The main reason for ECS was valve embolisation (n = 9; 56.3%), followed by perforation of the left/right ventricle with guide wire/pacemaker lead (n = 3; 18.8%) and annular rupture (n = 3; 18.8%). Procedural, 30-day and 1‑year mortality was 0%, 18.8% (n = 3) and 31.3% (n = 5), respectively. In-hospital stroke occurred in 1 patient (6.3%), a pacemaker was implanted at 30 days in 2 patients (12.5%), and major vascular complications did not occur.

CONCLUSION

ECS following complicated TAVI was performed in only a small number of cases. It had a high but acceptable perioperative and 30-day mortality, taking into account the otherwise lethal consequences. In case of valve embolisation, no periprocedural or 30-day mortality was observed for surgical aortic valve replacement (even in a redo setting), which supported the necessity to perform TAVI in centres with cardiac surgical backup on site.

National indication document and aortic valve replacement landscape in the Netherlands

INTRODUCTION

Based on European guidelines, transcatheter aortic valve implementation (TAVI) could be the therapy of choice in patients with severe aortic stenosis aged ≥ 75 years. In the Netherlands, there has been a debate between healthcare providers and the National Health Care Institute regarding reimbursement for TAVI, which resulted in an indication document that defines TAVI patients who are eligible for reimbursement. This document has been effective since 1 January 2021.

METHODS

We extracted data from the Netherlands Heart Registry for patients who underwent biological surgical aortic valve replacement (SAVR) or TAVI in the Netherlands from 2018 through 2021. We compared baseline characteristics and variables from the indication document for the subsequent years and age groups. We also analysed the annual SAVR/TAVI ratio.

RESULTS

The total number of patients treated with SAVR or TAVI was constant in 2018-2021. Baseline characteristics of patients treated with TAVI did not differ throughout the years. The SAVR/TAVI ratio shifted towards a higher percentage of TAVI from 2018 to 2019. From 2019 to 2020, the TAVI percentage was constant. Since the implementation of the indication document (in 2021), a change in the SAVR/TAVI ratio was not found either.

CONCLUSION

Since the implementation of the national indication document for AVR in 2021, no major effect was seen for the SAVR versus TAVI landscape in the Netherlands.

Potential effects of the hydrostatic pressure gradient on hyperemic and nonhyperemic pressure ratios

When measuring hyperemic and nonhyperemic pressure ratios with traditional sensor-tipped wires, the inevitable hydrostatic pressure gradient (HPG) may influence treatment decisions. This study aimed to simulate and analyze the effect of a hydrostatic pressure gradient on different indices of functional lesion severity. A hypothetical Pd-Pa height difference and subsequent hydrostatic pressure gradient based on previous literature was applied to the pressure measurements from the CONTRAST study. The effect on three indices of functional lesion severity (FFR, Pd/Pa, and dPR) was assessed and possible reclassifications in functional significance by the different indices were analyzed. In 602 pressure tracings, simulated hydrostatic pressure gradients led to an absolute change in Pd of 3.18 ± 1.30 mmHg, resulting in an overall increase in FFR, Pd/Pa, and dPR of 0.02 ± 0.04 for all indices (P = 0.69). Reclassification due to the hydrostatic pressure gradient when using dichotomous cutoff values occurred in 13.4, 22.3, and 20.6% for FFR, Pd/Pa, and dPR, respectively. The effect of hydrostatic pressure gradient correction differed among the coronary arteries and was most pronounced in the left anterior descending. When considering the gray zone for the different functional indices, the hydrostatic pressure gradient resulted in reclassification in only one patient out of the complete patient population (1/602; 0.17%). The hydrostatic pressure gradient can influence functional lesion assessment when using dichotomous cutoff values. When taking the gray zone into account, its effect is limited.NEW & NOTEWORTHY This study systematically simulated the effect of hydrostatic pressure gradients (HPG) on real-world hyperemic and nonhyperemic pressure ratios, showing correction for HPG leads to reclassification in functional significance from 13.4 to 22.3% for different functional indices. This was most pronounced in nonhyperemic pressure ratios. A new pressure guidewire (Wirecath) is unaffected by HPG. The ongoing PW-COMPARE study (NCT04802681) prospectively analyzes the magnitude and importance of HPG by simultaneous FFR measurements.

Transcatheter repair of massive primary mitral regurgitation: beyond the reach of the guidelines

A 58-year-old male with prior history of mechanical aortic valve replacement (AVR) in 2009 for severe symptomatic aortic regurgitation in a bicuspid aortic valve, and since 2013 a new-onset severe asymptomatic primary mitral regurgitation (MR) due to prolapse of the anterior mitral valve leaflet (AMVL) presented himself with acute heart failure. Based on current guidelines recommendations, this patient was not eligible for transcutaneous mitral valve edge-to-edge repair (TEER), as well he was found as too high risk for conventional mitral valve repair. However, as a last resort TEER was undertaken with an unconventional strategy, which resulted in resolution of the MR and improvement of clinical, biochemical findings.

Rationale and design of SAVI-AoS: A physiologic study of patients with symptomatic moderate aortic valve stenosis and preserved left ventricular ejection fraction

Background

Moderate aortic valve stenosis occurs twice as often as severe aortic stenosis (AS) and carries a similarly poor prognosis. Current European and American guidelines offer limited insight into moderate AS (MAS) patients with unexplained symptoms. Measuring valve physiology at rest while most patients experience symptoms during exertion might represent a conceptual limitation in the current grading of AS severity. The stress aortic valve index (SAVI) may delineate hemodynamically significant AS among patients with MAS.

Objectives

To investigate the diagnostic value of SAVI in symptomatic MAS patients with normal left ventricular ejection fraction (LVEF ≥ 50%): aortic valve area (AVA) > 1 cm² plus either mean valve gradient (MG) 15–39 mmHg or maximal aortic valve velocity (AOV max) 2.5–3.9 m/s. Short-term objectives include associations with symptom burden, functional capacity, and cardiac biomarkers. Long-term objectives include clinical outcomes.

Methods and results

Multicenter, non-blinded, observational cohort. AS severity will be graded invasively (aortic valve pressure measurements with dobutamine stress testing for SAVI) and non-invasively (echocardiography during dobutamine and exercise stress). Computed tomography (CT) of the aortic valve will be scored for calcium, and hemodynamics simulated using computational fluid dynamics. Cardiac biomarkers and functional parameters will be serially monitored. The primary objective is to see how SAVI and conventional measures (MG, AVA and Vmax) correlate with clinical parameters (quality of life survey, 6-minute walk test [6MWT], and biomarkers).

Conclusions

The SAVI-AoS study will extensively evaluate patients with unexplained, symptomatic MAS to determine any added value of SAVI versus traditional, resting valve parameters.

Prehospital triage of patients with suspected non-ST-segment elevation acute coronary syndrome: Rationale and design of the TRIAGE-ACS study

BACKGROUND

Patients with suspected non-ST-segment elevation acute coronary syndrome (NSTE-ACS) are currently transported and admitted to the nearest emergency department (ED) for risk stratification, diagnostic workup and treatment. Although such patients with NSTE-ACS can benefit from direct transfer to a PCI center for early invasive treatment, no reliable prehospital triage tools are available. Recently, the PreHEART score has been validated in the PreHEART study for prehospital triage of patients with suspected NSTE-ACS.

METHODS

The primary objective of the TRIAGE-ACS study, a prospective cohort study, is to determine whether prehospital triage using the PreHEART score can significantly reduce time from first medical contact to final diagnostics and revascularization in patients in need of coronary revascularization. The first cohort (control cohort; n = 500) is observatory and is used as a reference group for the second cohort. In the second cohort (interventional cohort; n = 500) patients are stratified in the ambulance for direct transfer to either a PCI or a non-PCI center, based on the PreHEART score. These two cohorts will be compared with each other. In total, 1000 patients will be included. Follow-up for endpoints will be performed by reviewing the medical record after 30 days, 1 year, and 2 years.

CONCLUSION

The TRIAGE-ACS study is the first prospective study to investigate the impact of prehospital triage using the PreHEART score on time to final invasive diagnostics and treatment in patients with NSTE-ACS in need of revascularization by transferring high risk patients directly to a PCI center and patients at a low risk of having an NSTE-ACS to a non-PCI center. Such triage strategy could potentially result in optimization of regional care for all ACS patients.

Hypothermia for Cardioprotection in Patients with St-Elevation Myocardial Infarction: Do Not Give It the Cold Shoulder Yet!

The timely revascularization of an occluded coronary artery is the cornerstone of treatment in patients with ST-elevation myocardial infarction (STEMI). As essential as this treatment is, it can also cause additional damage to cardiomyocytes that were still viable before reperfusion, increasing infarct size. This has been termed “myocardial reperfusion injury”. To date, there is still no effective treatment for myocardial reperfusion injury in patients with STEMI. While numerous attempts have been made to overcome this hurdle with various experimental therapies, the common denominator of these therapies is that, although they often work in the preclinical setting, they fail to demonstrate the same results in human trials. Hypothermia is an example of such a therapy. Although promising results were derived from experimental studies, multiple randomized controlled trials failed to do the same. This review includes a discussion of hypothermia as a potential treatment for myocardial reperfusion injury, including lessons learned from previous (negative) trials, advanced techniques and materials in current hypothermic treatment, and the possible future of hypothermia for cardioprotection in patients with STEMI.

Ultrastructural Characteristics of Myocardial Reperfusion Injury and Effect of Selective Intracoronary Hypothermia: An Observational Study in Isolated Beating Porcine Hearts

In acute myocardial infarction (AMI), myocardial reperfusion injury may undo part of the recovery after revascularization of the occluded coronary artery. Selective intracoronary hypothermia is a novel method aimed at reducing myocardial reperfusion injury, but its presumed protective effects in AMI still await further elucidation. This proof-of-concept study assesses the potential protective effects of selective intracoronary hypothermia in an ex-vivo, isolated beating heart model of AMI. In four isolated Langendorff perfused beating pig hearts, an anterior wall myocardial infarction was created by inflating a balloon in the mid segment of the left anterior descending (LAD) artery. After one hour, two hearts were treated with selective intracoronary hypothermia followed by normal reperfusion (cooled hearts). In the other two hearts, the balloon was deflated after one hour, allowing normal reperfusion (control hearts). Biopsies for histologic and electron microscopic evaluation were taken from the myocardium at risk at different time points: before occlusion (t = BO); 5 minutes before reperfusion (t = BR); and 10 minutes after reperfusion (t = AR). Electron microscopic analysis was performed to evaluate the condition of the mitochondria. Histological analyses included evaluation of sarcomeric collapse and intramyocardial hematoma. Electron microscopic analysis revealed intact mitochondria in the hypothermia treated hearts compared to the control hearts where mitochondria were more frequently damaged. No differences in the prespecified histological parameters were observed between cooled and control hearts at t = AR. In the isolated beating porcine heart model of AMI, reperfusion was associated with additional myocardial injury beyond ischemic injury. Selective intracoronary hypothermia preserved mitochondrial integrity compared to nontreated controls.

Predicting the infarct-related artery in STEMI from the surface ECG: independent validation of proposed criteria

AIMS

This study independently evaluated the diagnostic performance of electrocardiographic (ECG) criteria to predict the infarct-related artery (IRA) in patients with an acute ST-segment elevation myocardial infarction (STEMI). While a number of ECG criteria have been proposed to predict the IRA in STEMI, many of these "rules" came from modestly sized populations and did not undergo external validation. Therefore, we aimed to evaluate popular criteria from the literature in an independent cohort.

METHODS AND RESULTS

All acute STEMI cases over a 10-year period from a single hospital were retrospectively identified. We excluded patients with a missing pre-intervention ECG, irretrievable angiographic films, prior coronary artery bypass grafting, left bundle branch block, ventricular pacing, or not meeting strict STEMI criteria. After review of the angiograms for the IRA, cases with either no or multiple culprits were excluded. We included 480 subjects meeting STEMI criteria in inferior leads (192, 40%), anterior leads (184, 38%), both anterior and inferior leads (88, 18%), isolated lateral leads (nine, 2%), or a posterior pattern (seven, 1%). Notably, every pattern except isolated lateral STEMI included an IRA in both the right and left coronary arteries.

CONCLUSIONS

Existing ECG criteria to predict the IRA in STEMI have modest diagnostic performance when externally validated, and lower than in the original reports. Distinguishing the level of obstruction in the left anterior descending artery remains especially challenging. Hence, their use should be pragmatic when selecting an initial catheter for treating STEMI, since discordances will occur when compared to the actual angiogram.