Hepatic T1 Mapping as a Novel Cardio-Hepatic Axis Imaging Biomarker Early after STEMI.

BACKGROUND: The hepatic response after ST-elevation myocardial infarction (STEMI) may be associated with mortality and morbidity. We aimed to assess the cardio-hepatic axis post-STEMI using cardiovascular magnetic resonance (CMR). METHODS: This prospective, observational, single-centre study included consecutive STEMI patients who underwent CMR after primary angioplasty from January 2015 to January 2019. Standard infarct characteristics were analysed, and hepatic T1 and hepatic extracellular volume (ECV) were assessed using pre- and post-contrast T1-mapping sequences. The primary endpoint was the relationship between native hepatic T1-values and ischemic right ventricular (RV) involvement, determined by RV ejection fraction (EF) dysfunction and/or the presence of RV acute myocardial infarction (AMI). The diagnostic performance of hepatic T1 values for detecting RV involvement was assessed using the area under the receiver operating characteristic curve (AUC). RESULTS: Of 177 consecutive STEMI patients undergoing CMR, 142 were included. Patients with RV ischemic involvement, compared to those without, had significantly higher native hepatic T1 (p < 0.001) and hepatic ECV (p = 0.016). Hepatic T1 values demonstrated a good diagnostic performance in detecting RV involvement (AUC 0.826, p < 0.001) and correlated positively with NT-proBNP values (r = 0.754, p < 0.001). Patients with high hepatic T1 values (>605 ms) had significantly higher NT-proBNP levels (<0.001), larger RV end-diastolic volume (p < 0.001), lower RV-EF (p < 0.001), and a higher prevalence of RV AMI (p = 0.022) compared to those with hepatic T1 ≤ 605 ms, while left ventricular EF and infarct size were similar. Multivariable logistic regression analysis identified RV-EF (p = 0.010) and NT-proBNP values (p < 0.001) as independent predictors of increased hepatic T1 values. Patients with increased hepatic T1 values had a higher rate of re-hospitalization for heart failure at 17-month follow-up (12.1% vs 2.0%, p = 0.046). CONCLUSIONS: Hepatic T1 mapping has emerged as a possible novel imaging biomarker of the cardio-hepatic axis in STEMI, being associated with RV involvement and increased NT-proBNP values.

Outcomes and relevance of emergency percutaneous coronary angiography and intervention after resuscitated cardiac arrest: a retrospective study.

BACKGROUND: In patients resuscitated from cardiac arrest and displaying no ST-segment elevation on initial electrocardiogram (ECG), recent randomized trials indicated no benefits from early coronary angiography. How the results of such randomized studies apply to a real-world clinical context remains to be established. METHODS: We retrospectively analyzed a clinical database including all patients 18 yo or older admitted to our tertiary University Hospital from January 2017 to August 2020 after successful resuscitation of out-of-Hospital (OHCA) or In-Hospital (IHCA) cardiac arrest of presumed cardiac origin, and undergoing immediate coronary angiography, regardless of the initial rhythm and post-resuscitation ECG. The primary outcome of the study was survival at day 90 after cardiac arrest. Demographic data, characteristics of cardiac arrest, duration of resuscitation, laboratory values at admission, angiographic data and revascularization status were collected. Comparisons were performed according to the initial ECG (ST-segment elevation or not), and between survivors and non-survivors. Variables associated with the primary outcome were evaluated by univariate and multivariate regression analyses. RESULTS: We analyzed 147 patients (130 OHCA and 17 IHCA), including 67 with STEMI and 80 without STEMI (No STEMI). Immediate revascularization was performed in 65/67 (97%) STEMI and 15/80 (19%) no STEMI. Day 90 survival was significantly higher in STEMI (48/67, 72%) than no STEMI (44/80, 55%). In the latter patients, survival was not influenced by the revascularization status. In univariate and multivariate analyses, lower age, a shockable rhythm, shorter durations of no flow and low flow, and a lower initial blood lactate were associated with survival in both STEMI and no STEMI. In contrast, metabolic abnormalities, including lower initial plasma sodium and higher potassium were significantly associated with mortality only in the subgroup of no STEMI patients. CONCLUSIONS: Our results, obtained in a real-world clinical setting, indicate that an immediate coronary angiography is not associated with any survival advantage in patients resuscitated from cardiac arrest of presumed cardiac etiology without ST-segment elevation on initial ECG. Furthermore, we found that some early metabolic abnormalities may be associated with mortality in this population, which should deserve further investigation.

Paravalvular leak closure of a native aortic valve for cardiogenic shock post valvular surgery.

We describe the case of a 55-year-old patient with cardiogenic shock postsurgical mitral valve replacement, because of a native aortic valve paravalvular leak due to surgical trauma. The patient was successfully treated with a muscular ventricular septum defect device. To the best of our knowledge, this is the first report describing percutaneous device treatment of a native aortic valve paravalvular leak.

Thromboaspiration of a left-sided bioprosthetic valve thrombosis by a mini-access: the Lausanne novel procedure.

Left-sided bioprosthesis valve thrombosis (LSBVT) is a challenging complication necessitating invasive interventions. In this study, we introduce a novel, minimally invasive approach. We used a cerebral embolic protection system and an Occlutech cannula connected to an extracorporeal circuit, providing safer thrombus aspiration compared to the AngioVac system. This technique offers a promising alternative for high-risk patients with LSBVT.

Outcomes and Safety of Transcaval Transcatheter Aortic Valve Replacement: A Systematic Review and Meta-analysis.

BACKGROUND: The transcaval (TCv) vascular approach is increasingly used in transcatheter aortic valve replacement (TAVR) in patients unsuitable for the gold-standard transfemoral approach. We aimed to evaluate the efficacy, safety, and clinical outcomes associated with TCv-TAVR. METHODS: A systematic review and meta-analysis was conducted by searching PubMed/Medline, Embase, and the Cochrane Library for all articles assessing the TCv approach published through December 2023. Outcomes included 30-day and 1-year all-cause mortality (ACM), 30-day rehospitalisation, perioperative complications and postoperative complications at 30 days. The meta-analysis was registered on the PROSPERO database with the identifier CRD42024501921. RESULTS: A total of 8 studies with 467 patients were included. TCv-TAVR procedures achieved a success rate of 98.5%. TCv-TAVR was associated with a 30-day ACM rate of 6.1% (95% confidence interval [CI]: 3.9%-8.2%), a 1-year ACM rate of 14.9% (95% CI 2.3%-27.6%) and a 30-day rehospitalisation rate of 4.2% (95% CI -2.2% to 10.6%). Postoperative stroke or transient ischemic attack, major vascular complications, and major or life-threatening bleeding occurred in 3.3%, 8.7%, and 7.5% of cases, respectively. Cumulative meta-analyses showed a temporal trend of decreasing rates of vascular complications. CONCLUSIONS: The TCv approach in TAVR demonstrated a reassuring efficacy and safety profile, with mortality and postoperative complication rates similar to those reported for supra-aortic alternative TAVR access routes. The temporal decrease in vascular complications suggests potential improvements in procedural techniques and device technology. These findings further support the TCv approach as a viable option in patients ineligible for the transfemoral access. PROSPERO: CRD42024501921.

Exploring of gut microbiota features in dyslipidemia and chronic coronary syndrome patients undergoing coronary angiography.

Chronic coronary syndrome (CCS) has a high mortality rate, and dyslipidemia is a major risk factor. Atherosclerosis, a cause of CCS, is influenced by gut microbiota dysbiosis and its metabolites. The objective of this study was to study the diversity and composition of gut microbiota and related clinical parameters among CCS patients undergoing coronary angiography and dyslipidemia patients in comparison to healthy volunteers in Thailand. CCS patients had more risk factors and higher inflammatory markers, high-sensitivity C-reactive protein (hs-CRP) than others. The alpha diversity was lower in dyslipidemia and CCS patients than in the healthy group. A significant difference in the composition of gut microbiota was observed among the three groups. The relative abundance of Proteobacteria, Fusobacteria, Enterobacteriaceae, Prevotella, and Streptococcus was significantly increased while Roseburia, Ruminococcus, and Faecalibacterium were lower in CCS patients. In CCS patients, Lachnospiraceae, Peptostreptococcaceae, and Pediococcus were positively correlated with hs-CRP. In dyslipidemia patients, Megasphaera was strongly positively correlated with triglyceride (TG) level and negatively correlated with high-density lipoprotein cholesterol (HDL-C). The modification of gut microbiota was associated with changes in clinical parameters involved in the development of coronary artery disease (CAD) in CCS patients.

Comparison of atrial septal defect and patent foramen ovale in cryptogenic strokes.

OBJECTIVES: Paradoxical embolism from right-to-left shunt through atrial septal defect (ASD) and patent foramen ovale (PFO) is a well-accepted cause of "cryptogenic" strokes (CS). To better understand the pathogenic role of ASD, we compared ASD patients with CS having a high and low likelihood of being PFO-related. METHODS: In the Acute Stroke Registry and Analysis of Lausanne, we calculated prevalence of PFO and ASD in CS patients undergoing echocardiography, and calculated odds ratios (OR) when compared to non-CS. Using the Risk of Paradoxical Embolism (RoPE) score, we divided CS PFO patients in high (HL-PFO, RoPE 8-10) and low-likelihood (LL-PFO, RoPE 0-4) PFO-related stroke. We then performed univariate comparison of epidemiological, clinical and radiological variables of ASD patients with both PFO groups. RESULTS: Among all CS, prevalence of ASD and PFO were 1.3% and 36.8% respectively. When compared to non-CS, ASD and PFO were associated with CS (OR of 5.2, CI= 1.6-16.6, and 2.8, CI= 2.1-3.8). Compared with HL-PFO, ASD patients were older, more often female, had more cardiovascular risk factors and silent strokes. Compared with LL-PFO, ASD patients were younger, more often female, and had less risk factors. No differences were found for clinical and radiological characteristics and clinical outcome. CONCLUSION: ASD is a rare stroke risk factor for CS. Since characteristics of such patients lie in-between high and low-likelihood paradoxical PFO-strokes, a thorough work-up for other stroke mechanisms is warranted. Individual evaluation of the likelihood of the ASD being causative for stroke may be preferable over routine ASD closure.

Acute Response of the Noninfarcted Myocardium and Surrounding Tissue Assessed by T2 Mapping After STEMI.

BACKGROUND: ST-segment elevation myocardial infarction (STEMI) is associated with a systemic and local inflammatory response with edema. However, their role at the tissue level is poorly characterized. OBJECTIVES: This study aims to characterize T2 values of the noninfarcted myocardium (NIM) and surrounding tissue and to investigate prognostic relevance of higher NIM T2 values after STEMI. METHODS: A total of 171 consecutive patients with STEMI without prior cardiovascular events who underwent cardiac magnetic resonance after primary percutaneous coronary intervention were analyzed in terms of standard infarct characteristics. Edema of the NIM, liver, spleen, and pectoralis muscle was assessed based on T2 mapping. Follow-up was available for 130 patients. The primary endpoint was major adverse cardiac events (MACE), defined as cardiovascular death, myocardial infarction, unplanned coronary revascularization or rehospitalization for heart failure. The median time from primary percutaneous coronary intervention to cardiac magnetic resonance was 3 days (IQR: 2-5 days). RESULTS: Higher (above the median value of 45 ms) T2 values in the NIM area were associated with larger infarct size, microvascular obstruction, and left ventricular dysfunction and did not correlate with C-reactive protein, white blood cells, or T2 values of the pectoralis muscle, liver, and spleen. At a median follow-up of 17 months, patients with higher (>45 ms) NIM T2 values had increased risk of MACE (P < 0.001) compared with subjects with NIM T2 values ≤45 ms, mainly caused by a higher rate of myocardial reinfarction (26.3% vs 1.4%; P < 0.001). At multivariable analysis, higher NIM T2 values independently predicted MACE (HR: 2.824 [95% CI: 1.254-6.361]; P = 0.012). CONCLUSIONS: Higher NIM T2 values after STEMI are independently associated with worse cardiovascular outcomes, mainly because of higher risk of myocardial infarction.

Extrathoracic Against Intrathoracic Vascular Accesses for Transcatheter Aortic Valve Replacement: A Systematic Review With Meta-Analysis.

Alternative vascular accesses to transfemoral access for transcatheter aortic valve replacement (TAVR) can be divided into intrathoracic (IT)-transapical and transaortic- and extrathoracic (ET)-transcarotid, transsubclavian, and transaxillary. This study aimed to compare the outcomes and safety of IT and ET accesses for TAVR as alternatives to transfemoral access. A systematic review with meta-analysis was performed by searching PubMed/MEDLINE and EMBASE databases for all studies comparing IT-TAVR with ET-TAVR published until April 2023. Outcomes included in-hospital or 30-day all-cause mortality (ACM), 1-year ACM, postoperative and 30-day complications. A total of 18 studies with 6,800 IT-TAVR patients and 5,032 ET-TAVR patients were included. IT accesses were associated with a significantly higher risk of in-hospital or 30-day ACM (relative risk 1.99, 95% confidence interval 1.67 to 2.36, p <0.001), and 1-year ACM (relative risk 1.31, 95% confidence interval 1.21 to 1.42, p <0.001). IT-TAVR patients presented more often with postoperative life-threatening bleeding, 30-day new-onset atrial fibrillation or flutter, and 30-day acute kidney injury needing renal replacement therapy. The risks of postoperative permanent pacemaker implantation and significant paravalvular leak were lower with IT-TAVR. ET-TAVR patients were more likely to be directly discharged home. There was no statistically significant difference regarding the 30-day risk of stroke. Compared with ET-TAVR, IT-TAVR was associated with higher risks of in-hospital or 30-day ACM, 1-year ACM and higher risks for some critical postprocedural and 30-day complications. Our results suggest that ET-TAVR could be considered as the first-choice alternative approach when transfemoral access is contraindicated.

Case report: Stenosis turned leak and turned stenosis-complications of paravalvular prosthetic leak closure with a plug device.

Background: Paravalvular leak is one of the most common complications and is among the most important prognostic factors of short- and long-term mortality after transcatheter aortic valve implantation (TAVI). Percutaneous valvular leak repair constitutes a first-line treatment for paravalvular leaks and is associated with high success rates and few serious complications nowadays. To the best of our knowledge, this is the first case where placement of the device through the stenting of the bioprosthesis resulted in creating a new symptomatic stenosis that required surgery. Case summary: We present a case of a patient with low-flow, low-gradient aortic stenosis treated with transfemoral implantation of a biological aortic prosthesis. One month after the procedure, the patient presented with acute pulmonary oedema and a paravalvular leak was discovered, which was corrected by percutaneous repair with a plug device. Five weeks after the valvular leak repair, the patient was readmitted for heart failure. At this time, a new aortic stenosis and paravalvular leak were diagnosed and the patient was referred for surgery. The new aortic mixed diseased was caused by the positioning of the plug device through the valve's metal stenting, which resulted in a paravalvular leak and pressed against the valve's leaflets, causing valvular stenosis. The patient was referred for surgical replacement and evolved well afterward. Conclusion: This case illustrates a rare complication of a complex procedure, and it highlights the need for multidisciplinary decisions and good cooperation between the cardiology and cardiac surgery teams to develop better criteria in the selection of the appropriate technique for managing paravalvular leaks after TAVI.

Meta-Analysis of the Prognostic Significance of Carotid Artery Stenosis in Patients Who Underwent Transcatheter Aortic Valve Implantation.

Stroke is a known complication of both transcatheter aortic valve implantation (TAVI) and carotid artery stenosis (CAS). Whether CAS is a predictor of worse prognosis after TAVI is unclear. We performed a meta-analysis to assess the impact of CAS on the incidence of neurovascular complications and mortality after TAVI. We searched PubMed/MEDLINE and EMBASE databases from inception to January 2023. CAS was defined by ≥50% stenosis of at least 1 carotid artery. Studies comparing CAS versus non-CAS TAVI populations were included. Patients' baseline characteristics and 30-day clinical outcomes were extracted. End points included the 30-day incidence of neurovascular complications (stroke or transient ischemic attack) and 30-day all-cause mortality. We identified six studies, totaling 6,763 patients in the CAS group and 23,861 patients in the non-CAS group. Patients with CAS had a higher prevalence of hypertension, diabetes mellitus, dyslipidemia, previous myocardial infarction, coronary artery bypass graft, peripheral artery disease, previous neurovascular disease, and chronic kidney disease. There was no significant difference in the rates of 30-day neurovascular complications between CAS and non-CAS groups (relative risk 1.23, 95% confidence interval 0.63 to 2.40, p = 0.54). CAS was associated with a higher risk of 30-day all-cause mortality (relative risk 1.28, 95% confidence interval 1.12 to 1.47, p <0.001), not found in a sensitivity analysis. In conclusion, patients with CAS presented with a significantly higher co-morbidity burden. CAS was not associated with an increased risk of 30-day neurovascular complications. 30-day mortality was higher in the CAS group but that may be a surrogate of the heavy co-morbidity burden of patients with CAS.

Ultrathin-strut vs thin-strut drug-eluting stents for multi and single-stent lesions: A lesion-level subgroup analysis of 2 randomized trials.

BACKGROUND: Whether ultrathin-strut stents are particularly beneficial for lesions requiring implantation of more than 1 stent is unknown. METHODS: In a post-hoc lesion-level analysis of 2 randomized trials comparing ultrathin-strut biodegradable polymer Sirolimus-eluting stents (BP-SES) vs thin-strut durable polymer Everolimus-eluting stents (DP-EES), lesions were stratified into multistent lesions (MSL) vs single-stent lesions (SSL). The primary endpoint was target lesion failure (TLF), a composite of lesion-related unclear/cardiac death, myocardial infarction (MI), or revascularization, at 24 months. RESULTS: Among 5328 lesions in 3397 patients, 1492 (28%) were MSL (722 with BP-SES, 770 with DP-EES). At 2 years, TLF occurred in 63 lesions (8.9%) treated with BP-SES and 60 lesions (7.9%) treated with DP-EES in the MSL-group (subdistibution hazard ratio [SHR], 1.13; 95% CI, 0.77-1.64; P = .53), and in 121 (6.4%) and 136 (7.4%) lesions treated with BP-SES and DP-EES respectively (SHR, 0.86; 95% CI, 0.62-1.18; P = .35) in the SSL-group (P for interaction = .241). While the rates of lesion-related MI or revascularization were significantly lower in SSL treated with BP-SES as compared to DP-EES (3.5% vs 5.2%; SHR, 0.67; 95% CI 0.46-0.97; P = .036), no significant difference was observed in MSL (7.1% vs 5.4%; SHR, 1.31; 95% CI 0.85-2.03; P = .216) with significant interaction between groups (P for interaction = .014). CONCLUSIONS: Rates of TLF are similar between ultrathin-strut BP-SES and thin-strut DP-EES in MSL and SSL. The use of ultrathin-strut BP-SES vs thin-strut DP-EES did not prove to be particularly beneficial for the treatment of multistent lesions. TRIAL REGISTRATION: Post-hoc analysis from the BIOSCIENCE (NCT01443104) and BIOSTEMI (NCT02579031) trials.

Intracoronary Brachytherapy for Restenosis: 20 Years of Follow-Up.

BACKGROUND/PURPOSE: Intracoronary brachytherapy (ICB) has mainly been used to treat in-stent restenosis following percutaneous coronary intervention and was virtually abandoned about 20 years ago. However, patients treated with this strategy are still alive and some teams continue to perform this therapy. We aimed to investigate the very long-term clinical outcome of patients treated with ICB. METHODS/MATERIALS: A total of 173 consecutive patients who had been treated with ICB at a large tertiary referral centre between 1998 and 2003 were included. The primary endpoint of the study was all-cause mortality. The secondary endpoints were as follows: occurrence of major adverse cardiac events (MACE, defined as all-cause death, non-fatal myocardial infarction, or target vessel revascularization), cardiac death, and presence of angina at the end of follow-up. RESULTS: Patients' mean age at the time of ICB was 64 ± 10 years and 77 % were male. Restenosis (bare metal stent vs. balloon angioplasty) was the only indication for ICB. Unstable angina was present in 34 % of the patients. Follow-up was available for 166 patients. After a mean follow-up of 20 ± 1.3 years, 66 % of the patients had died (including 74 patients (67 %) with cardiac death). Cumulative MACE rate at 20 years was 96 %. CONCLUSIONS: Very long-term follow-up of patients with in-stent restenosis treated with ICB confirmed a high all-cause mortality rate mainly due to cardiac causes and MACEs.

Caplacizumab for treating subacute intra-stent thrombus occurring despite efficacious double anti-platelet treatment and anticoagulation: a case report.

Background: Acute and subacute stent thromboses are a rare complication associated with high mortality and morbidity occurring in ∼1.5% of patients treated with primary percutaneous intervention for ST-elevation myocardial infarction (STEMI). Recent publications describe a potential role of the von Willebrand factor (VWF) in thrombus formation at sites of critical coronary stenosis in STEMI. Case summary: We describe a 58-year-old woman with STEMI at initial presentation, who suffered subacute stent thrombosis despite good stent expansion, efficacious dual antiplatelet therapy, and therapeutic anticoagulation. Because of very high VWF values, we administered N-acetylcysteine in order to depolymerize VWF, but the drug was not well tolerated. Since the patient was still symptomatic, we used caplacizumab in order to prevent VWF from interacting with platelets. Under this treatment, the clinical and angiographic course was favourable. Discussion: Considering a modern view of intracoronary thrombus pathophysiology, we describe an innovative treatment approach, which eventually ended in a favourable outcome.

[Cardiology: what's new in 2022]. / Cardiologie : ce qui a changé en 2022.

The year of 2022 was marked by many novelties in the fields of interventional cardiology, heart failure, electrophysiology, cardiac imaging, and congenital heart disease. These advances will certainly change our daily practice, on top of improving the diagnosis and treatment of many heart conditions. In addition, the European Society of Cardiology has updated its guidelines on pulmonary hypertension, ventricular arrhythmias and sudden death, cardiovascular assessment of patients undergoing non-cardiac surgery. The members of the Cardiology division of Lausanne University Hospital (CHUV) here present the publications which they considered to be the most important of the past year.

L'année 2022 a été marquée par de nombreuses nouveautés dans les domaines de la cardiologie interventionnelle, de l'insuffisance cardiaque, de l'électrophysiologie, de l'imagerie cardiaque et des cardiopathies congénitales. Ces progrès vont certainement faire évoluer notre pratique quotidienne, en plus d'améliorer le diagnostic et le traitement de nombreuses cardiopathies. Par ailleurs, la Société européenne de cardiologie a mis à jour ses recommandations portant sur l'hypertension pulmonaire, les arythmies ventriculaires et la mort subite ainsi que le bilan cardiologique avant une chirurgie non cardiaque. Les membres du Service de cardiologie du CHUV vous présentent ici les travaux qui leur ont semblé être les plus importants de l'année écoulée.

Neurovascular Outcomes in Relation With Carotid Artery Stenosis in Patients Undergoing Transcatheter Aortic Valve Implantation.

INTRODUCTION: Data regarding the prevalence of carotid artery stenosis (CAS) in patients undergoing transcatheter aortic valve implantation (TAVI) are scarce. Whether CAS, especially severe or bilateral, is a predictor of worse prognosis after TAVI is unknown. We aimed to address these questions. METHODS: We included all patients who underwent TAVI between 2018 and 2021. Using pre-TAVI carotid Doppler ultrasound, atherosclerosis of the right and left carotid internal arteries was assessed. CAS was defined as moderate (50%-69% stenosis, peak systolic velocity of 125-230 cm/sec) or severe (≥70% stenosis, peak systolic velocity of >230 cm/sec). When both carotid arteries presented with ≥50% stenosis, CAS was defined as bilateral. Endpoints included the 30-day incidence of stroke or transient ischemic attack (TIA), 30-day all-cause mortality, and periprocedural complications. RESULTS: Among 448 patients, 56 (12.5%) had CAS, of which 15 had bilateral and 15 had severe CAS. Patients with CAS were more often men and had higher rates of peripheral artery disease, coronary artery disease, and previous percutaneous coronary intervention. There was no association between CAS and 30-day stroke or TIA (adjusted hazard ratio [aHR], 2.55; 95% confidence interval [CI], 0.73-8.91; P=.14), even when considering severe CAS only. However, a significant association was found between bilateral CAS and 30-day stroke or TIA (aHR, 8.399; 95% CI, 1.603-44.000; P=.01). No association between CAS and 30-day mortality or periprocedural complications was found. CONCLUSIONS: CAS is common among TAVI patients. While CAS as a whole was not a predictor of neurovascular complications, the subgroup of bilateral CAS was associated with an increased risk of stroke.

Comparison of the prognostic value of impaired stress myocardial blood flow, myocardial flow reserve, and myocardial flow capacity on low-dose Rubidium-82 SiPM PET/CT.

BACKGROUND: The most reliable quantitative variable on Rubidium-82 (82Rb) cardiac PET/CT for predicting major adverse cardiovascular events (MACE) has not been characterized with low-dose silicon photomultipliers (SiPM) technology, which allows halving injected activity and radiation dose delivering less than 1.0 mSv in a 70-kg individual. METHODS AND RESULTS: We prospectively enrolled 234 consecutive participants with suspected myocardial ischemia. Participants underwent 82Rb cardiac SiPM PET/CT (5 MBq/kg) and were followed up for MACE over 652 days (interquartile range 559-751 days). For each participant, global stress myocardial blood flow (stress MBF), global myocardial flow reserve (MFR), and regional severely reduced myocardial flow capacity (MFCsevere) were measured. The Youden index was used to select optimal thresholds. In multivariate analysis after adjustments for clinical risk factors, reduced global stress MBF < 1.94 ml/min/g, reduced global MFR < 1.98, and regional MFCsevere > 3.2% of left ventricle emerged all as independent predictors of MACE (HR 4.5, 3.1, and 3.67, respectively, p < 0.001). However, only reduced global stress MBF remained an independent prognostic factor for MACE after adjusting for clinical risk factors and the combined use of global stress MBF, global MFR, and regional MFCsevere impairments (HR 2.81, p = 0.027). CONCLUSION: Using the latest SiPM PET technology with low-dose 82Rb halving the standard activity to deliver < 1 mSv for a 70-kg patient, impaired global stress MBF, global MFR, and regional MFC were powerful predictors of cardiovascular events, outperforming traditional cardiovascular risk factors. However, only reduced global stress MBF independently predicted MACE, being superior to global MFR and regional MFC impairments.

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.