Impact of vessel volume on thermodilution measurements in patients with coronary microvascular dysfunction.

BACKGROUND: Two invasive methods are available to estimate microvascular resistance: bolus and continuous thermodilution. Comparative studies have revealed a lack of concordance between measurements of microvascular resistance obtained through these techniques. AIMS: This study aimed to examine the influence of vessel volume on bolus thermodilution measurements. METHODS: We prospectively included patients with angina with non-obstructive coronary arteries (ANOCA) undergoing bolus and continuous thermodilution assessments. All patients underwent coronary CT angiography to extract vessel volume. Coronary microvascular dysfunction was defined as coronary flow reserve (CFR) < 2.0. Measurements of absolute microvascular resistance (in Woods units) and index of microvascular resistance (IMR) were compared before and after volumetric adjustment. RESULTS: Overall, 94 patients with ANOCA were included in this study. The mean age was 64.7 ± 10.8 years, 48% were female, and 19% had diabetes. The prevalence of CMD was 16% based on bolus thermodilution, while continuous thermodilution yielded a prevalence of 27% (Cohen's Kappa 0.44, 95% CI 0.23-0.65). There was no correlation in microvascular resistance between techniques (r = 0.17, 95% CI -0.04 to 0.36, p = 0.104). The adjustment of IMR by vessel volume significantly increased the agreement with absolute microvascular resistance derived from continuous thermodilution (r = 0.48, 95% CI 0.31-0.63, p < 0.001). CONCLUSIONS: In patients with ANOCA, invasive methods based on coronary thermodilution yielded conflicting results for the assessment of CMD. Adjusting IMR with vessel volume improved the agreement with continuous thermodilution for the assessment of microvascular resistance. These findings strongly suggest the importance of considering vessel volume when interpreting bolus thermodilution assessment.

Asymptomatic Aortic Stenosis: From Risk Stratification to Treatment.

Our understanding of the natural history of aortic stenosis has significantly increased over the last decade. There have been considerable advances in the diagnosis and risk stratification of patients with aortic stenosis and in surgical and anesthetic techniques. In addition, transcatheter aortic valve replacement has established itself as a viable alternative to surgical management. Inevitably, these developments have raised questions regarding the merits of waiting for symptom onset in asymptomatic patients with severe aortic stenosis before offering treatment. Recent observational and randomized trial data suggest that early intervention in asymptomatic patients with severe aortic stenosis and normal left ventricular function may confer a prognostic advantage to a watchful waiting strategy. In this review, we highlight advances in the management and risk stratification of patients with asymptomatic severe aortic stenosis with particular consideration of recent findings supporting early valvular intervention.

Measuring Absolute Coronary Flow and Microvascular Resistance by Thermodilution: JACC Review Topic of the Week.

Diagnosing coronary microvascular dysfunction remains challenging, primarily due to the lack of direct measurements of absolute coronary blood flow (Q) and microvascular resistance (Rµ). However, there has been recent progress with the development and validation of continuous intracoronary thermodilution, which offers a simplified and validated approach for clinical use. This technique enables direct quantification of Q and Rµ, leading to precise and accurate evaluation of the coronary microcirculation. To ensure consistent and reliable results, it is crucial to follow a standardized protocol when performing continuous intracoronary thermodilution measurements. This document aims to summarize the principles of thermodilution-derived absolute coronary flow measurements and propose a standardized method for conducting these assessments. The proposed standardization serves as a guide to ensure the best practice of the method, enhancing the clinical assessment of the coronary microcirculation.

Assessing the Impact of Prolonged Averaging of Coronary Continuous Thermodilution Traces.

Continuous Thermodilution is a novel method of quantifying coronary flow (Q) in mL/min. To account for variability of Q within the cardiac cycle, the trace is smoothened with a 2 s moving average filter. This can sometimes be ineffective due to significant heart rate variability, ventricular extrasystoles, and deep inspiration, resulting in a fluctuating temperature trace and ambiguity in the location of the "steady state". This study aims to assess whether a longer moving average filter would smoothen any fluctuations within the continuous thermodilution traces resulting in improved interpretability and reproducibility on a test-retest basis. Patients with ANOCA underwent repeat continuous thermodilution measurements. Analysis of traces were performed at averages of 10, 15, and 20 s to determine the maximum acceptable average. The maximum acceptable average was subsequently applied as a moving average filter and the traces were re-analysed to assess the practical consequences of a longer moving average. Reproducibility was then assessed and compared to a 2 s moving average. Of the averages tested, only 10 s met the criteria for acceptance. When the data was reanalysed with a 10 s moving average filter, there was no significant improvement in reproducibility, however, it resulted in a 12% diagnostic mismatch. Applying a longer moving average filter to continuous thermodilution data does not improve reproducibility. Furthermore, it results in a loss of fidelity on the traces, and a 12% diagnostic mismatch. Overall, current practice should be maintained.

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.

ChatGPT takes on the European Exam in Core Cardiology: an artificial intelligence success story?

Chat Generative Pre-trained Transformer (ChatGPT) is currently a trending topic worldwide triggering extensive debate about its predictive power, its potential uses, and its wider implications. Recent publications have demonstrated that ChatGPT can correctly answer questions from undergraduate exams such as the United States Medical Licensing Examination. We challenged it to answer questions from a more demanding, post-graduate exam-the European Exam in Core Cardiology (EECC), the final exam for the completion of specialty training in Cardiology in many countries. Our results demonstrate that ChatGPT succeeds in the EECC.

[Can smart devices and AI in cardiology improve clinical practice?] / Les dispositifs intelligents et l'IA en cardiologie peuvent-ils améliorer la pratique clinique ?

Remote monitoring is becoming increasingly popular among healthcare professionals and patients for diagnosing and treating heart disease. Several smart devices connected to smartphones have been developed and validated in recent years, but their clinical use is still limited. Significant advances in the field of artificial intelligence (AI) are also revolutionizing several fields, yet the impact that these innovations could have on routine clinical practice is still unknown. We review the evidence and uses of the main smart devices currently available as well as the latest applications of AI in the field of cardiology, with the aim to ultimately evaluate the potential of this technology to transform modern clinical practice.

Le monitorage à distance devient de plus en plus populaire parmi les praticiens de la santé pour le diagnostic et la surveillance des maladies cardiaques. Plusieurs dispositifs « intelligents ¼ et connectés aux smartphones ont été développés et validés durant ces dernières années, mais leur utilisation clinique est toujours limitée. Bien que les progrès de l'intelligence artificielle (IA) soient en train de révolutionner plusieurs domaines, l'impact que ces innovations pourront avoir dans le monde médical est toujours inconnu. Le but de cet article est de passer en revue les principaux dispositifs disponibles et de comprendre les applications actuelles de l'IA en cardiologie, afin de mieux saisir dans quelle mesure ils sont susceptibles de transformer notre pratique clinique quotidienne.

Twenty-year trends in the prevalence of modifiable cardiovascular risk factors in young acute coronary syndrome patients hospitalized in Switzerland.

AIMS: Modifiable cardiovascular risk factors (RFs) play a key role in the development of coronary artery disease. We evaluated 20-year trends in RF prevalence among young adults hospitalized with acute coronary syndromes (ACS) in Switzerland. METHODS AND RESULTS: Data were analysed from the Acute Myocardial Infarction in Switzerland (AMIS) Plus registry from 2000 to 2019. Young patients were defined as those aged <50 years. Among 58 028 ACS admissions, 7073 (14.1%) were young (median 45.6 years, IQR 42.0-48.0), of which 91.6% had at least one modifiable RF and 59.0% had at least two RFs. Smoking was the most prevalent RF (71.4%), followed by dyslipidaemia (57.3%), hypertension (35.9%), obesity (21.7%), and diabetes (10.1%). Compared with older patients, young patients were more likely to be obese (21.7% vs. 17.4%, P < 0.001) and active smokers (71.4% vs. 33.9%, P < 0.001). Among young patients, between 2000 and 2019, there was a significant increase in the prevalence of hypertension from 29.0% to 51.3% and obesity from 21.2% to 27.1% (both Ptrend < 0.001) but a significant decrease in active smoking from 72.5% to 62.5% (Ptrend = 0.02). There were no significant changes in the prevalence of diabetes (Ptrend = 0.32) or dyslipidaemia (Ptrend = 0.067). CONCLUSION: Young ACS patients in Switzerland exhibit a high prevalence of RFs and are more likely than older patients to be obese and smokers. Between 2000 and 2019, RF prevalence either increased or remained stable, except for smoking which decreased but still affected approximately two-thirds of young patients in 2019. Public health initiatives targeting RFs in young adults in Switzerland are warranted.

We evaluated the prevalence of risk factors (RFs) among young patients admitted with ACS in Switzerland between 2000 and 2019. Young ACS patients in Switzerland exhibited a high prevalence of RFs. There was a significant increase in the prevalence of hypertension and obesity. Despite a significant decrease, active smoking remained the most prevalent RF. These findings strongly suggest that public health initiatives targeting RFs in young adults in Switzerland are warranted.

Deep learning-based prediction of future myocardial infarction using invasive coronary angiography: a feasibility study.

BACKGROUND: Angiographic parameters can facilitate the risk stratification of coronary lesions but remain insufficient in the prediction of future myocardial infarction (MI). AIMS: We compared the ability of humans, angiographic parameters and deep learning (DL) to predict the lesion that would be responsible for a future MI in a population of patients with non-significant CAD at baseline. METHODS: We retrospectively included patients who underwent invasive coronary angiography (ICA) for MI, in whom a previous angiogram had been performed within 5 years. The ability of human visual assessment, diameter stenosis, area stenosis, quantitative flow ratio (QFR) and DL to predict the future culprit lesion (FCL) was compared. RESULTS: In total, 746 cropped ICA images of FCL and non-culprit lesions (NCL) were analysed. Predictive models for each modality were developed in a training set before validation in a test set. DL exhibited the best predictive performance with an area under the curve of 0.81, compared with diameter stenosis (0.62, p=0.04), area stenosis (0.58, p=0.05) and QFR (0.67, p=0.13). DL exhibited a significant net reclassification improvement (NRI) compared with area stenosis (0.75, p=0.03) and QFR (0.95, p=0.01), and a positive nonsignificant NRI when compared with diameter stenosis. Among all models, DL demonstrated the highest accuracy (0.78) followed by QFR (0.70) and area stenosis (0.68). Predictions based on human visual assessment and diameter stenosis had the lowest accuracy (0.58). CONCLUSION: In this feasibility study, DL outperformed human visual assessment and established angiographic parameters in the prediction of FCLs. Larger studies are now required to confirm this finding.

Diagnostic performance of angiography-derived fractional flow reserve in patients with NSTEMI.

Noninvasive methods of estimating invasively measured fractional flow reserve (FFRinvasive ) are actively being explored, aiming to avoid the use of an invasive pressure wire and the administration of hyperemia-inducing drugs. Coronary angiography-derived FFR (FFRangio ) has already demonstrated its diagnostic performance in the context of stable coronary artery disease. However, its applicability in the context of non-ST-segment elevation myocardial infarction (NSTEMI) has yet to be established. We sought to determine the diagnostic performance of FFRangio exclusively in patients presenting with NSTEMI. We performed a prospective, single-center, single-arm, double-blinded study comparing FFR calculated by FFRangio to FFRinvasive in NSTEMI patients. FFRinvasive was measured in all angiographically intermediate lesions (30%-70% stenosis) and was then compared to FFRangio which was calculated at the same position, by a blinded operator. The primary endpoints were the sensitivity and specificity of FFRangio for predicting FFRinvasive using a cut-off value of ≤0.80. Among 100 NSTEMI patients who were screened, 46 patients with 60 vessels in total underwent FFRinvasive and were included in the study. The mean value of FFRinvasive was 0.83 ± 0.3 with 22 (36%) being ≤0.80 while the mean FFRangio was 0.82 ± 0.1 with 22 (36%) being ≤0.80. FFRangio exhibited a sensitivity of 95.5%, a specificity of 97.4%, and a diagnostic accuracy of 96.7%. FFRangio can precisely and noninvasively estimate FFRinvasive in acute coronary syndromes and may have a role in guiding treatment decisions related to angiographically intermediate coronary lesions in this context. WHAT IS KNOWN: FFRangio has demonstrated its diagnostic performance in validation studies, as a noninvasive and cost-effective method in the context of stable coronary artery disease but its performance has never been exclusively evaluated in NSTEMI patients. WHAT IS NEW: The present prospective single-center study demonstrates the excellent diagnostic performance of FFRangio in detecting functionally significant coronary artery stenosis in the setting of NSTEMI, providing more confidence in utilizing FFRangio in this population, avoiding the risk of an invasive pressure wire and the administration of hyperemia-inducing drugs. WHAT IS NEXT: Future randomized trials evaluating FFRangio -guided treatment of coronary artery disease (stable or ACS) are now needed to definitively establish the role of FFRangio in the physiological assessment of coronary lesions.

Case Report: A First Case of Spontaneous Coronary Artery Dissection Potentially Associated With Scuba Diving.

Background: Scuba diving has rarely been associated with spontaneous arterial dissection. However, all documented cases have involved the cervicocranial arteries. Case summary: We report the first case of spontaneous coronary artery dissection (SCAD) potentially associated with scuba diving in a 65-year-old female with no medical history or known cardiovascular risk factors. She presented with sudden-onset chest pain during her descent whilst scuba diving on holiday. An initial ECG revealed transient abnormalities, but due to normal initial blood tests, a reassuring echocardiogram, and the resolution of her symptoms, she was discharged from hospital without a clear diagnosis. During her subsequent presentation to our hospital 1 week later, electrocardiographic evidence of an inferior myocardial infarction (MI) was noted, with an echocardiogram revealing regional wall motion abnormalities of the left ventricular inferior wall. Coronary angiography revealed the presence of a SCAD of the posterior left ventricular artery, with cardiac magnetic resonance imaging confirming the presence of an inferior MI. As recommended in the majority of cases of SCAD, this case was managed conservatively with a favorable clinical course. Conclusion: This is the first reported case of SCAD potentially associated with scuba diving. It highlights the importance of considering SCAD in patients presenting with sudden-onset chest pain during physical activity, especially in female patients (including older patients) with no cardiovascular risk factors. Furthermore, it serves as a reminder that symptoms during scuba diving are not always related to decompression illness.

Narrow complex tachycardia with discordant 12-lead RP intervals.

We present a case of supraventricular tachycardia (SVT) with discordant RP intervals on 12­lead ECG, rendering the diagnosis initially challenging. However, clues present on the ECG during SVT along with an ECG in sinus rhythm helped to elucidate the mechanism and the underlying diagnosis.

[Cardiology]. / Cardiologie.

Significant advances have been made in 2021 in the areas of interventional cardiology, heart failure, cardiac imaging, electrophysiology and congenital heart disease. In addition to improving the screening, diagnosis and management of many heart diseases, these advances will change our daily practice. Moreover, the European Society of Cardiology has updated its guidelines on heart failure, valve disease, cardiac pacing and cardiovascular disease prevention. As in previous years, members of the Cardiology division of Lausanne University Hospital (CHUV) came together to select and present to you the papers that they considered to be the most important of the past year.

De nombreux progrès ont été réalisés en 2021 dans les domaines de la cardiologie interventionnelle, de l'insuffisance cardiaque, de l'imagerie cardiaque, de l'électrophysiologie et des cardiopathies congénitales. En plus d'améliorer le dépistage, le diagnostic et la prise en charge de nombreuses cardiopathies, ces avancées vont faire évoluer notre pratique quotidienne. Par ailleurs, la Société européenne de cardiologie a mis à jour ses recommandations portant sur l'insuffisance cardiaque, les valvulopathies, la stimulation cardiaque et la prévention des maladies cardiovasculaires. Comme les années précédentes, les membres du Service de cardiologie du CHUV se sont réunis pour sélectionner et vous présenter les travaux qui leur ont semblé être les plus importants de l'année écoulée.

CCN family member 1 (CCN1) is an early marker of infarct size and left ventricular dysfunction in STEMI patients.

BACKGROUND AND AIMS: CCN family member 1 (CCN1) has recently been proposed as a novel biomarker of myocardial injury, improving prediction of 30-day and one-year mortality following acute coronary syndromes. Among ST-elevation myocardial infarction (STEMI) patients, we evaluated the utility of CCN1 measured immediately before primary percutaneous coronary intervention (PPCI) as a predictor of two earlier endpoints: final myocardial infarct size and post-infarction left ventricular ejection fraction (LVEF). Furthermore, we evaluated the impact of CCN1 on the discriminatory power of the CADILLAC score. METHODS: STEMI patients were obtained from the SPUM-ACS cohort. Serum CCN1 was measured prior to PPCI. Linear regression assessed the association between CCN1, peak creatinine kinase (CK), and post-infarction LVEF. Cox models assessed an association between CCN1 and 30-day all-cause mortality. RESULTS: CCN1 was measured in 989 patients with a median value of 706.2 ng/l (IQR 434.3-1319.6). A significant correlation between CCN1, myocardial infarct size (peak CK) and LVEF was observed in univariate and multivariate analysis (both p < 0.001). Even among patients with normal classical cardiac biomarker levels at the time of PPCI, CCN1 correlated significantly with final infarct size. CCN1 significantly improved prediction of 30-day all-cause mortality by the CADILLAC score (C-index 0.864, likelihood-ratio chi-square test statistic 6.331, p = 0.012; IDI 0.026, p= 0.050). CONCLUSIONS: Compared with classical cardiac biomarkers, CCN1 is potentially the earliest predictor of final myocardial infarct size and post-infarction LVEF. CCN1 improved the discriminatory capacity of the CADILLAC score suggesting a potential role in the very-early risk stratification of STEMI patients.

Future culprit detection based on angiography-derived FFR.

OBJECTIVES: We sought to characterize the hemodynamic impact of mild coronary artery disease (CAD) using quantitative flow ratio (QFR, an angiography-derived fractional flow reserve [FFR]) in a population of patients with only non-significant CAD at baseline that subsequently experienced a myocardial infarction (MI). BACKGROUND: The discriminatory value of FFR in patients with mild CAD remains imperfect. METHODS: We retrospectively included patients who underwent invasive coronary angiography for an MI, in whom another angiogram had been performed within the previous 5 years. Three-dimensional quantitative coronary angiography, QFR, and lesion length analysis were conducted on lesions responsible for the MI (future culprit lesions, [FCL]) as well as on control lesions (non-culprit lesions, [NCL]). RESULTS: Eighty-three FCL and 117 NCL were analyzed in 83 patients: FCL were more severe (median % diameter of stenosis [DS] 39.1% [29.8; 45.7] vs. 29.8% [25.0; 37.2], p < .001), had lower QFR values (0.94 [0.86; 0.98] vs. 0.98 [0.96; 1.00], p < .001) and tended to be longer (15.2 mm [10.0; 27.3] vs. 12.7 mm [9.3; 22.4], p = .070) than NCL. In lesions with an interval < 2 years between baseline angiography and MI, the difference in QFR was more pronounced compared to the lesions with a longer interval (FCL: 0.92 [0.85; 0.97] vs. NCL: 0.98 [0.94; 1.00], p < .001 and FCL: 0.96 [0.88; 1.00] vs. NCL: 0.98 [0.96;1.00], p = .006 respectively) CONCLUSION: Mild coronary stenoses that are subsequently responsible for an MI (FCL) exhibit a higher DS and lower QFR years before the event. Furthermore, FCL with a lower QFR at baseline appear to lead earlier to MI.