A study of ChatGPT in facilitating Heart Team decisions on severe aortic stenosis

BACKGROUND

Multidisciplinary Heart Teams (HTs) play a central role in the management of valvular heart diseases. However, the comprehensive evaluation of patients' data can be hindered by logistical challenges, which in turn may affect the care they receive.

AIMS

This study aimed to explore the ability of artificial intelligence (AI), particularly large language models (LLMs), to improve clinical decision-making and enhance the efficiency of HTs.

METHODS

Data from patients with severe aortic stenosis presented at HT meetings were retrospectively analysed. A standardised multiple-choice questionnaire, with 14 key variables, was processed by the OpenAI Chat Generative Pre-trained Transformer (GPT)-4. AI-generated decisions were then compared to those made by the HT.

RESULTS

This study included 150 patients, with ChatGPT agreeing with the HT's decisions 77% of the time. The agreement rate varied depending on treatment modality: 90% for transcatheter valve implantation, 65% for surgical valve replacement, and 65% for medical treatment.

CONCLUSIONS

The use of LLMs offers promising opportunities to improve the HT decision-making process. This study showed that ChatGPT's decisions were consistent with those of the HT in a large proportion of cases. This technology could serve as a failsafe, highlighting potential areas of discrepancy when its decisions diverge from those of the HT. Further research is necessary to solidify our understanding of how AI can be integrated to enhance the decision-making processes of HTs.

Head-to-head comparison of two angiography-derived fractional flow reserve techniques in patients with high-risk acute coronary syndrome: A multicenter prospective study

BACKGROUND

FFRangio and QFR are angiography-based technologies that have been validated in patients with stable coronary artery disease. No head-to-head comparison to invasive fractional flow reserve (FFR) has been reported to date in patients with acute coronary syndromes (ACS).

METHODS

This study is a subset of a larger prospective multicenter, single-arm study that involved patients diagnosed with high-risk ACS in whom 30-70% stenosis was evaluated by FFR. FFRangio and QFR - both calculated offline by 2 different and blinded operators - were calculated and compared to FFR. The two co-primary endpoints were the comparison of the Pearson correlation coefficient between FFRangio and QFR with FFR and the comparison of their inter-observer variability.

RESULTS

Among 134 high-risk ACS screened patients, 59 patients with 84 vessels underwent FFR measurements and were included in this study. The mean FFR value was 0.82 ± 0.40 with 32 (38%) being ≤0.80. The mean FFRangio was 0.82 ± 0.20 and the mean QFR was 0.82 ± 0.30, with 27 (32%) and 25 (29%) being ≤0.80, respectively. The Pearson correlation coefficient was significantly better for FFRangio compared to QFR, with R values of 0.76 and 0.61, respectively (p = 0.01). The inter-observer agreement was also significantly better for FFRangio compared to QFR (0.86 vs 0.79, p < 0.05). FFRangio had 91% sensitivity, 100% specificity, and 96.8% accuracy, while QFR exhibited 86.4% sensitivity, 98.4% specificity, and 93.7% accuracy.

CONCLUSION

In patients with high-risk ACS, FFRangio and QFR demonstrated excellent diagnostic performance. FFRangio seems to have better correlation to invasive FFR compared to QFR but further larger validation studies are required.

TAVR as an Alternative to SAVR for Pure Native Aortic Regurgitation

Although transcatheter aortic valve replacement was originally fulfilling an unmet clinical need in the elderly population suffering from tricuspid aortic valve stenosis, its use has been progressively expanded to other groups of patients. In this review, we focus on pure native aortic valve regurgitation, which is in most cases a degenerative disease and therefore frequently diagnosed in elderly patients with comorbidities. Symptoms tend to appear late in the disease, when left ventricular dilation and systolic dysfunction are associated owing to excessive volume overload. It is often combined with a dilated aortic annulus and ascending aorta. Surgical aortic valve replacement remains the criterion standard treatment for severe aortic regurgitation. However, for patients at prohibitive surgical risk, transcatheter aortic valve replacement represents an attractive alternative. Various technical challenges are the absence of calcium at the level of the annulus, which means there are no anchoring points or fluoroscopic landmarks, the difficulty of valve sizing, and the increased stroke volume secondary to the aortic regurgitation, making valve deployment more unstable than in the setting of aortic stenosis. The first-generation transcatheter valves were associated with a higher mortality rate and lower procedural success related to increased risk of paravalvular leak and valve migration requiring a second valve or annular rupture than the more recent off-label or on-label transcatheter valves. Early studies with the dedicated on-label devices showed safety and promising results and will undoubtedly serve in the future a growing number of patients with native aortic regurgitation at prohibitive risk for surgery.

Degenerated Transcatheter Aortic Valve Replacement: Investigation and Management Options

With the expansion of transcatheter aortic valve replacement (TAVR) to younger and lower-surgical-risk patients, many younger and less comorbid patients will be treated with TAVR and are expected to have a life expectancy that will exceed the durability of their transcatheter heart valve. Consequently, the number of patients requiring reintervention will undoubtedly increase in the near future. Redo-TAVR and TAVR explantation followed by surgical aortic valve replacement are the different therapeutic options in the event of bioprosthetic valve failure and the need for reintervention. Patients often anticipate being able to benefit from a redo-TAVR in the event of bioprosthetic valve failure after TAVR, despite the lack of long-term data and the risk of unfavourable anatomy. Our understanding of the feasibility of redo-TAVR is constantly improving thanks to bench test studies and growing worldwide experience. However, much remains unknown. In clinical practice, one of the heart team's objectives is to anticipate the need to reaccess the coronary arteries and implant a second or even a third valve when life expectancy may exceed the durability of the transcatheter heart valve. In this review, we address key definitions in the diagnosis of structural valve deterioration and bioprosthetic valve failure, as well as patient selection and procedural planning for redo-TAVR to reduce periprocedural risk, optimise hemodynamic performance, and maintain coronary access. We describe the bench testing and literature in the redo-TAVR and TAVR explantation fields.

[Aortic stenosis: TAVI for all patients?]

Over the last 21 years, the paradigm has shifted from an initial use of TAVI for inoperable aortic stenosis cases to recognition of its benefits for all categories of patients. Since 2021, the European Society of Cardiology has recommended first-line transfemoral TAVI from the age of 75 for all categories of patients with aortic stenosis (high, intermediate, low risk). However, in Switzerland, the Federal Office of Public Health currently places a restriction on the reimbursement of low-risk patients, which is expected to be reassessed in 2023. Surgery remains the best therapeutic option for patients with an unfavorable anatomy and for those whose life expectancy exceeds the potential durability of the valve. In this article we will discuss the evidence supporting TAVI, its current indications and initial complications as well as areas for improvement to potentially further expand its indications.

Recurrent pneumonia post atrial fibrillation ablation: do not forget to look for pulmonary vein stenosis

A man in his 50s presented with persistent chest pain, haemoptysis, cough and dyspnoea 5 months after undergoing catheter ablation for atrial fibrillation (AF). Several chest CT scans suggested pneumonia. Despite adequate treatment for recurrent pneumonia, symptoms persisted. While reviewing the initial chest CT, a partial venous infarction of the left lower lobe associated with severe left inferior pulmonary vein stenosis (PVS) was diagnosed. Stenting of the left inferior pulmonary vein with a vascular bare metal stent was performed, guided by fluoroscopy and transoesophageal echocardiography. Dual antiplatelet therapy (aspirin/clopidogrel) was introduced for 3 months, followed by long-term aspirin monotherapy. The treatment resulted in relief of his symptoms and the resolution of pulmonary opacities on chest CT. Despite low frequency, AF ablation remains the most common cause of acquired PVS. As highlighted in this case, symptoms are not specific and include recurrent pulmonary infection with delayed management.

Prognostic Implications of the Novel Pulmonary Hypertension Definition in Patients with Aortic Stenosis after Transcatheter Valve Replacement

Introduction: Pulmonary hypertension (PH), traditionally defined as a mean pulmonary artery pressure (PAP) ≥ 25 mmHg, is associated with poor outcomes in patients undergoing a transcatheter aortic valve replacement (TAVR) for severe aortic stenosis (AS). Recently, a novel definition for PH has been proposed, placing the cut-off value of mean PAP at 20 mmHg, and introducing pulmonary vascular resistance as an exclusive indicator for the pre-capillary involvement. In light of the novel criteria, whether PH still preserves its prognostic significance remains unknown. Methods: The study population consisted of 380 patients with AS, who underwent a right heart catheterization before TAVR. The cohort was divided according to the presence of PH (n = 174, 45.7%) or not. Patients with PH were further divided into the following groups: (1) Pre-capillary PH ((Pre-capPH), n = 46, 12.1%); (2) Isolated post-capillary PH ((IpcPH), n = 78, 20.5%); (3) Combined pre and post-capillary PH ((CpcPH), n = 82, 21.6%). The primary endpoint was all-cause mortality at 1 year. Results: A total of 246 patients (64.7%) exhibited mean PAP > 20 mmHg. Overall, the presence of PH was associated with higher 1-year mortality rates (hazard ratio (HR) 2.8, 95% CI: 1.4−5.8, p = 0.004). Compared to patients with no PH, Pre-capPH and CpcPH (but not IpcPH) were related to higher 1-year mortality (HR 2.7, 95% CI: 1.0−7.2, p = 0.041 and HR 3.9, 95% CI: 1.8−8.5, p = 0.001, respectively). This remained significant even after the adjustment for baseline comorbidities. Conclusions: Pre-interventional PH according to the novel hemodynamic criteria, is linked with poor outcomes in patients undergoing TAVR for severe AS. However, this is mainly driven by patients with mean PAP ≥ 25 mmHg. Patients with a pre-capillary PH component as defined by increased PVR present an even worse prognosis as compared to patients with isolated post-capillary or no PH who present comparable 1-year mortality rates.

Arterial Wave Reflection and Aortic Valve Stenosis: Diagnostic Challenges and Prognostic Significance

Introduction

Arterial wave reflection is an important component of the left ventricular afterload, affecting both pressure and flow to the aorta. The aim of the present study was to evaluate the impact of wave reflection on transvalvular pressure gradients (TPG), a key parameter for the evaluation of aortic valve stenosis (AS), as well as its prognostic significance in patients with AS undergoing a transcatheter aortic valve replacement (TAVR).

Materials and Methods

The study population consisted of 351 patients with AS (mean age 84 ± 6 years, 43% males) who underwent a complete hemodynamic evaluation before the TAVR. The baseline assessment included right and left heart catheterization, transthoracic echocardiography, and a thorough evaluation of the left ventricular afterload by means of wave separation analysis. The cohort was divided into quartiles according to the transit time of the backward pressure wave (BWTT). Primary endpoint was all-cause mortality at 1 year.

Results

Early arrival of the backward pressure wave was related to lower cardiac output (Q1: 3.7 ± 0.9 lt/min vs Q4: 4.4 ± 1.0 lt/min, p &lt; 0.001) and higher aortic systolic blood pressure (Q1: 132 ± 26 mmHg vs Q4: 117 ± 26 mmHg, p &lt; 0.001). TPG was significantly related to the BWTT, patients in the arrival group exhibiting the lowest TPG (mean TPG, Q1: 37.6 ± 12.7 mmHg vs Q4: 44.8 ± 14.7 mmHg, p = 0.005) for the same aortic valve area (AVA) (Q1: 0.58 ± 0.35 cm2 vs 0.61 ± 0.22 cm2, p = 0.303). In multivariate analysis, BWTT remained an independent determinant of mean TPG (beta 0.3, p = 0.002). Moreover, the prevalence of low-flow, low-gradient AS with preserved ejection fraction was higher in patients with early arterial reflection arrival (Q1: 33.3% vs Q4: 14.9%, p = 0.033). Finally, patients with early arrival of the reflected wave (Q1) exhibited higher all-cause mortality at 1 year after the TAVR (unadjusted HR: 2.33, 95% CI: 1.17–4.65, p = 0.016).

Conclusion

Early reflected wave arrival to the aortic root is associated with poor prognosis and significant aortic hemodynamic alterations in patients undergoing a TAVR for AS. This is related to a significant decrease in TPG for a given AVA, leading to a possible underestimation of the AS severity.

Volume-Outcome Relationship in Surgical and Cardiac Transcatheter Interventions with a Focus on Transcatheter Aortic Valve Implantation

“Practice makes perfect” is an old saying that can be true for complex interventions. There is a strong and persistent relationship between high volume and better outcomes with more than 300 studies being reported on the subject. The more complex the procedure, the greater the volume-outcome relationship is. Failure to rescue was shown to be one of the factors explaining higher mortality rates post complex surgery. High-volume centers provide a better safety net, thanks to the structure and better protocols, and low-volume operators have better results at high-volume centers than at low-volume centers. Finally, effort should be made to regroup complex procedures in high-volume centers, but without compromising patient access to the procedures. Adaptation to local and geographic constraints is important.

The Biolimus A9-coated BioFreedom™ stent: from clinical efficacy to real-world evidence

In this state-of-the-art review, we present the findings and a critical analysis of the Leaders Free trial program, evaluating outcomes of a new stent-generation based on polymer-free technology, in this case the BioFreedom^™ (Biosensors Europe, Switzerland), in patients at high bleeding risk (HBR). Polymer-free drug-coated stents were designed to obtain a device with the antirestenotic benefits of drug-eluting stents but without the polymer coating as potential trigger for delayed arterial wall healing and subsequent late ischemic adverse events, causing a prolonged dependence on dual antiplatelet therapy after stenting. This offers therefore the potential of a promising device-based strategy in a complex growing population of patients with combined HBR and high thrombosis risk, due to the possible reduction of antithrombotic duration.