Voltage and propagation mapping: New tools to improve successful ablation of atrioventricular nodal reentry tachycardia.

INTRODUCTION: Mapping system is useful in ablation of atrioventricular nodal reentry tachycardia (AVNRT) and localization of anatomic variances. Voltage mapping identifies a low voltage area in the Koch triangle called low-voltage-bridge (LVB); propagation mapping identifies the collision point (CP) of atrial wavefront convergence. We conducted a prospective study to evaluate the relationship between LVB and CP with successful site of ablation and identify standard value for LVB. MATERIALS AND METHODS: Three-dimensional (3D) maps of the right atria were constructed from intracardiac recordings using the ablation catheter. Cut-off values on voltage map were adjusted until LVB was observed. On propagation map, atrial wavefronts during sinus rhythm collide in the site representing CP, indicating the area of slow pathway conduction. Ablation site was selected targeting LVB and CP site, confirmed by anatomic position on fluoroscopy and atrioventricular ratio. RESULTS: Twenty-seven consecutive patients were included. LVB and CP were present in all patients. Postprocedural evaluation identified standard cut-off of 0.3-1 mV useful for LVB identification. An overlap between LVB and CP was observed in 23 (85%) patients. Procedure success was achieved in all patient with effective site at first application in 22 (81%) patients. There was a significant correlation between LVB, CP, and the site of effective ablation (p = .001). CONCLUSION: We found correlation between LVB and CP with the site of effective ablation, identifying a voltage range useful for standardized LVB identification. These techniques could be useful to identify ablation site and minimize radiation exposure.

Unmasking of a significant left main stenosis in a patient with high left ventricular pressures.

As identification of left main (LM) stenoses has prognostic and therapeutic relevance, a precise anatomic and/or functional characterization of angiographically intermediate LM stenoses, by using intravascular ultrasound (IVUS) and fractional flow reserve (FFR) respectively, is crucial (1). However, increased left ventricular (LV) pressures might affect FFR measurements (2). Here we describe the case of a patient with chronic coronary syndrome and severe LV dysfunction in whom coronary angiography revealed an intermediate LM stenosis and catheterization identified an increased LV end-diastolic pressure. FFR measurement showed disproportionally higher FFR values compared with the minimal luminal area assessed by IVUS. When cardiac output was artificially augmented by using Impella for assisting percutaneous coronary intervention, the value of FFR measurement turned out proportional to what expected for the degree of anatomical stenosis. This discrepancy between anatomic and functional measurement may be a sign of coronary autoregulation dysfunction and therefore could help to identify high-risk patients in whom the use of a mechanical support device is more beneficial during percutaneous revascularization.

Return towards normality in admissions for myocardial infarction after the lockdown removal for COVID-19 outbreak in Italy.

BACKGROUND: Investigations demonstrated a decrease of admissions for myocardial infarction (MI) during the CoronaVirus Disease-19 (COVID-19) outbreak. No study has evaluated the time required to reverse this downward curve of MI admissions. METHODS: This is a retrospective analysis on patients (N = 2415) admitted to the Emergency Departments for acute MI in nine Italian centers. Primary endpoint was the incidence rates (IRs) of MI admissions in the post-lockdown COVID-19 period (case-period: from May 4 to July 12, 2020) vs. the following control periods: January 1-February 19, 2020 (pre-lockdown period); February 20-May 3, 2020 (intra-lockdown period); May 4-July 12, 2019 (inter-year non-COVID-19 period). RESULTS: IR of admissions for MI in the post-lockdown period was higher than the intra-lockdown period (IR ratio, IRR: 1.60, 95% CI 1.42-1.81; p = 0.0001), was lower than the pre-lockdown period (IRR: 0.86, 0.77-0.96; p = 0.009) and similar to the inter-year non-COVID-19 period (IRR: 0.96, 0.87-1.07; p = 0.47). Within the case period, the increase in MI admissions was more pronounced in earlier vs later weeks (IRR 1.19, 95% CI 1.02-1.38, p = 0.024) and, compared to the inter-year control period, was significant for non ST-segment elevation MI (IRR: 1.25, 95% CI 1.08-1.46, p = 0.004), but was not observed for ST-segment elevation MI (STEMI), where hospitalizations were reduced (IRR 0.76, 95% CI 0.65-0.88, p = 0.0001). CONCLUSIONS: Our study first indicates an increase in the number of admissions for MI after the removal of the national lockdown for COVID-19 in Italy. This increase was prevalent in the first weeks following the lockdown removal, but was under-represented in STEMI patients.

Drug-eluting compared to bare metal stents in patients with end-stage renal disease on dialysis: a meta-analysis.

AIMS: To systematically review literature comparing bare metal stent (BMS) to drug-eluting stent (DES) in end-stage renal disease (ESRD) patients on dialysis. ESRD patients on dialysis often suffer from accelerated atherosclerosis and higher rate of stent-related complications including major adverse cardiovascular events. Because dialysis usually qualifies ineligibility for randomized clinical trials, an evidenced-based stent choice for these patients is scarce. METHODS: PUBMED, CINHAL, COCHRANE, EMBASE and WEB OF SCIENCE were searched for studies comparing BMS vs. DES outcome in ESRD patients on dialysis. RESULTS: Twenty studies including 64 232 patients were considered. The use of DES was significantly associated with a reduction in all-cause mortality [odds ratio (OR) 0.83, 95% confidence interval (CI) 0.76-0.89], death from a cardiovascular cause (OR 0.80, 95% CI 0.76-0.84) and target lesion revascularization/target vessel revascularization (OR 0.73, 95% CI 0.53-1.00). No significant difference was found in stent thrombosis (OR 1.08, 95% CI 0.50-2.33) and myocardial infarction incidence (OR 0.91, 95% CI 0.69-1.20). CONCLUSIONS: Our meta-analysis shows a significant reduction in all-cause and cardiovascular mortality with the use of DES over BMS in dialyzed patients. Despite the lack of randomized studies, systematic use of DES in these high-risk patients should thus reasonably be considered as a first option in percutaneous coronary intervention candidates.

Drug eluting stents are superior to bare metal stents to reduce clinical outcome and stent-related complications in CKD patients, a systematic review, meta-analysis and network meta-analysis.

Aims To compare clinical outcome in Chronic kidney disease (CKD) patients receiving coronary stents according to stent type BMS versus DES and 1st generation versus 2nd generation DES. Methods and Results PubMed, Cinhal, Cochrane, Embase, and Web of Science were searched for studies including CKD patients. CKD was defined as eGFR < 60 mL/min. We selected n = 35 articles leading to 376 169 patients, of which 76 557 CKD patients receiving BMS n = 35,807, 1st generation DES n = 37,650, or 2nd generation DES n = 3100. Patient receiving DES, compared to BMS, had a 18% lower all-cause mortality (RR 0.82, 95%CI 0.71-0.94). The composite of death or myocardial infarction (MI) was lower in DES patients (RR 0.78, 95%CI 0.67-0.91), as was stent thrombosis (ST) (RR 0.57, 95%CI 0.34-0.95), target vessel/lesion revascularization (TVR/TLR) (RR 0.69, 95%CI 0.57-0.84) and death for cardiovascular cause (RR 0.43, 95%CI 0.25-0.74). We also found a gradient between 1st and 2nd generation DES, through BMS. Second, compared to 1st generation DES, were associated with further relative risk (RR) reduction of -18% in of all-cause death, and lower incidence of stent-related clinical events: -39% RR of ST risk; -27 RR of TVR/TLR risk. Conclusions DES in CKD patients undergoing PCI were superior to BMS in reducing major adverse clinical events. This was possibly explained, by a lower risk of stent-related events as ST and TVR or TLR. Second, compared to 1st generation DES may furtherly reduce clinical events.

Infections, immunity and atherosclerosis: pathogenic mechanisms and unsolved questions.

The role of inflammation and immunity in the pathogenesis and clinical manifestations of atherosclerotic disease has been widely studied. Common infectious diseases can be associated with a chronic inflammatory state which is the hallmark of atherosclerosis, thus suggesting a possible link between the two pathological conditions. Therefore, a great number of studies have tested the "infection hypothesis", but their results are conflicting. Nevertheless, several molecular and biological mechanisms possibly involved in the complex relationship between infections, immune response, vascular wall damage and atherosclerosis onset and progression have been described. The purpose of this article is to offer an overview of the principal mechanisms and molecular pathways that probably constitute the most relevant biological substrate on which the infection hypothesis is founded; some of these mechanisms are not fully understood yet. Nevertheless, their comprehension could be essential for the development of new preventive and therapeutic strategies.

Baseline C-reactive protein serum levels and in-stent restenosis pattern after m-TOR inhibitors drug-eluting stent implantation.

BACKGROUND: A diffuse pattern of in-stent restenosis (ISR) has been shown to have a worse prognosis when compared to a focal pattern. It is still unknown whether baseline C-reactive protein (CRP) levels predict ISR pattern. METHODS: Our database was searched retrospectively for patients presenting with ISR after m-TOR inhibitor drug-eluting stent (DES) implantation from January 2007 to December 2009. Angiographic restenosis patterns were evaluated according to the simplified Mehran classification and patients were allocated either to the diffuse or focal pattern group. Predictors of restenosis pattern were assessed among clinical, angiographic, procedural and laboratory data, including baseline high-sensitivity CRP, recorded at the time of the first percutaneous intervention. RESULTS: 72 patients (age, 65 ± 9 years; male sex, 64%) found to have ISR after DES implantation were enrolled. 34 patients presented with a focal pattern, whereas 38 patients presented with a diffuse pattern. At multivariate analysis, CRP levels were the only independent predictor of a diffuse ISR pattern [odds ratio, 2.5; 95% confidence interval, 1.4-4.3; p = 0.001)]. Rising CRP tertiles were associated with an increased rate of diffuse pattern (13% versus 26% versus 61%; p for trend = 0.0001). CONCLUSION: Baseline CRP serum levels are associated with a diffuse ISR pattern after m-TOR inhibitor DES implantation. These findings suggest that baseline inflammatory reactivity may contribute to aggressive restenosis occurring despite drug elution.