Martin Horváth

Effect of catheter-based patent foramen ovale closure on the occurrence of arterial bubbles in scuba divers.

OBJECTIVES This study sought to evaluate the effect of catheter-based patent foramen ovale (PFO) closure on the occurrence of arterial bubbles after simulated dives. BACKGROUND PFO is a risk factor of decompression sickness in divers due to paradoxical embolization of bubbles. To date, the effectiveness of catheter-based PFO closure in the reduction of arterial bubbles has not been demonstrated. METHODS A total of 47 divers (age 35.4 ± 8.6 years, 81% men) with a PFO (PFO group) or treated with a catheter-based PFO closure (closure group) were enrolled in this case-controlled observational trial. All divers were examined after a simulated dive in a hyperbaric chamber: 34 divers (19 in the PFO group, 15 in the closure group) performed a dive to 18 m for 80 min, and 13 divers (8 in the PFO group, 5 in the closure group) performed a dive to 50 m for 20 min. Within 60 min after surfacing, the presence of venous and arterial bubbles was assessed by transthoracic echocardiography and transcranial color-coded sonography, respectively. RESULTS After the 18-m dive, venous bubbles were detected in 74% of divers in the PFO group versus 80% in the closure group (p = 1.0), and arterial bubbles were detected in 32% versus 0%, respectively (p = 0.02). After the 50-m dive, venous bubbles were detected in 88% versus 100%, respectively (p = 1.0), and arterial bubbles were detected in 88% versus 0%, respectively (p < 0.01). CONCLUSIONS No difference was observed in the occurrence of venous bubbles between the PFO and closure groups, but the catheter-based PFO closure led to complete elimination of arterial bubbles after simulated dives. (Nitrogen Bubble Detection After Simulated Dives in Divers With PFO and After PFO Closure; NCT01854281).

Effect of conservative dive profiles on the occurrence of venous and arterial bubbles in divers with a patent foramen ovale: A pilot study

Patent foramen ovale (PFO) is a risk factor for decompression sick-ness(DCS)indiversduetoparadoxicalembolizationofnitrogenbubblesformed in peripheral blood during decrease of ambient pressure [1].Inour previous study we have demonstrated that catheter-based PFO clo-sure prevented right-to-left shunting of bubbles and might preventDCS recurrence [2]. However, the question of PFO closure is still debat-able [3].Also,randomizedclinicaldataarelackinginthis field.Therefore,the majority of divers are currently not referred for PFO closure, andvarious conservative dive profiles (CDP) are recommended to preventunprovoked DCS (i.e., without violation of decompression regimen) [4].Unfortunately, to date, the safety of these CDP has not been tested in di-verswithPFO.Theaimofthisstudywastotesttheeffectofdivetimeandascent rate restrictions on the occurrence of venous and arterial bubblesin diverswith PFO after simulated dives.We compareda standardly rec-ommended no-decompression dive [5] and a stricter regimen withslower ascent to the same control dive, which was previously used totest the efficacy of catheter-based PFO closure [2].Wescreenedatotalof 532 consecuti vediversforPFOusingtranscra-nialcolorcodedsonography(TCCS).ThediagnosisofPFOwascon firmedbytransesophagealechocardiography.Forty-sixdivers(36.4±10 years;72% men) with a significant PFO (grade 3 according to the internationalconsensus criteria [6]) who had previously not undergone PFO closurewere enrolled in this pilot study. All divers performed a simulated diveto 18 m in a hyperbaric chamber. Divers were randomized into threegroups: group A (n = 13; 36.5 ± 9 years; 77% men) performed a stan-dard Buhlmann regimen no-decompression dive (dive time 51 min,ascent rate 10 m/min), group B (n = 14, 40.9 ± 12 years; 64% men)performed the same regimen with a slower ascent (51 min, 5 m/min),and a control group (n = 19; 33.0 ± 8 years; 74% men) performed astaged-decompression dive according to the US Navy decompressionregimen (80 min, 9 m/min, decompression stop 7 min at 3 m). Within60 min of surfacing, the presence of venous and arterial bubbles wasassessed. Venous bubbles were assessed by pulse wave Doppler in therightventricularout flowtract (RVOT),andarterialbubbles byTCCS dur-ing native breathing and after Valsalva maneuvers, as described previ-ously [2]. The study was approved by the local ethics committee and allpatients signed an informed consent.In all divers, visualization of RVOT and the middle cerebral artery waspossible. The occurrence of arterial and venous bubbles is summarized inFig. 1. There was significantly lower occurrence of venous bubbles ingroups A and B compared to controls (for group A, 31% vs. 74%, p =0.03; for group B, 14% vs. 74%, p b 0.01). The reduction in arterial bubbleoccurrencewasnotsigni ficantingroupAcomparedtocontrols,buttherewas elimination of arterial bubbles in group B (for group A, 8% vs. 32%,p = 0.42;forgroupB,0%vs.32%,p= 0.03).Therewasnosigni ficantdif-ference in venous or arterial bubble occurrence between groups A and B(venous, 31% vs. 14%, p = 0.38; arterial, 8% vs. 0%, p = 0.48). All diverswere observed for any DCS symptoms 24 h after the simulated dive. Inthe control group transient neurological symptoms (headache, unusualfatigue, and transitory visual disturbances) were present in 21% of divers,no DCS symptoms were observed in group A (p = 0.13) or B (p = 0.12).Generally, the aim of our research is to stratify the risk of DCS indiverswithPFOandtofindtheoptimalmanagementstrategyforsymp-tomatic divers, including potential catheter-based PFO closure. In our

The role of near-infrared spectroscopy in the detection of vulnerable atherosclerotic plaques

Coronary artery disease is the leading cause of mortality worldwide. Most acute coronary syndromes are caused by a rupture of a vulnerable atherosclerotic plaque which can be characterized by a lipid-rich necrotic core with an overlying thin fibrous cap. Many vulnerable plaques can cause angiographically mild stenoses due to positive remodelling, which is why the extent of coronary artery disease may be seriously underestimated. In recent years, we have witnessed a paradigm shift in interventional cardiology. We no longer focus solely on the degree of stenosis; rather, we seek to determine the true extent of atherosclerotic disease. We seek to identify high-risk plaques for improvement in risk stratification of patients and prevention. Several imaging methods have been developed for this purpose. Intracoronary near-infrared spectroscopy is one of the most promising. Here, we discuss the possible applications of this diagnostic method and provide a comprehensive overview of the current knowledge.

First-in-man near-infrared spectroscopy proof of lipid-core embolization during carotid artery stenting

Intravascular near-infrared spectroscopy (NIRS), which has been used in over 5,000 patients to identify the lipid-core plaques (LCP) that cause coronary events, may also assist in the characterization of the carotid atherosclerotic lesions predisposing to stroke. To our knowledge, this is the first report of the use of NIRS in a patient undergoing carotid artery stenting (CAS).

Predicting Hemodynamic Changes of Cerebral Blood Flow during Temporal Carotid Occlusion: A Review of Current Knowledge with Implication for Carotid Artery Stenting.

Carotid artery disease (CAD) plays an important role in the stroke development and its prevalence increases with aging of the population. Its wide variability of clinical manifestation ranges from incidental asymptomatic finding to devastating or fatal stroke, although cerebral collateral circulation is considered one of the major modifying factors. Over time, carotid artery stenting (CAS) has evolved into a reputable method for the treatment of patients with severe CAD. With expanding use of proximal protection systems resembling surgical clamp, there is an increasing demand to understand collateral cerebral circulation to protect patients from periprocedural hypoperfusion, which increases the risk of cerebral events. Transcranial Doppler ultrasound (TCD) is a useful tool allowing monitoring in real time during procedure patient́s cerebral hemodynamic status providing the operator with valuable information. Its role in predicting periprocedural hypoperfusion is, however, less well established. In this article, we discuss the role of cerebral collateral circulation, summarize the current knowledge regarding its evaluation with TCD and suggest future implications for CAS.

Patent Foramen Ovale in Recreational and Professional Divers: An Important and Largely Unrecognized Problem

Patent foramen ovale (PFO) is associated with an increased risk of decompression sickness (DCS) in divers that results from a paradoxical embolization of nitrogen bubbles. The number of scuba divers worldwide is estimated in the millions, and the prevalence of PFO is 25%-30% in adults. It is interesting that despite these numbers, many important issues regarding optimal screening, risk stratification, and management strategy still remain to be resolved. Recently published data suggest the possible effectiveness of both PFO closure and conservative diving measures in preventing arterial gas embolization. This review aims to introduce the basic principles of physiology and the pathophysiology of bubble formation and DCS, summarize the current literature on PFO and diving, and review the possibilities of diagnostic workup and management.

Catheter-based endovenous laser ablation of saphenous veins in the treatment of symptomatic venous reflux: Early results

Uvod: Katetrizacni endovenozni laserova ablace (EVLA) je běžně uživana alternativa chirurgicke lecby varixů dolnich koncetin a postupně se stava metodou volby. V teto observacni studii jsme si kladli za cil prokazat, zda je tato metoda bezpecna a proveditelna v souboru neselektovaných pacientů a zda je možno provest ablaci vice segmentů v ramci jednoho výkonu.Metodika: V obdobi od unora 2010 do března 2016 byla provedena EVLA celkem v 1 209 žilnich segmentech u 1 117 po sobě nasledujicich pacientů (74 % ženy) s žilnim refluxem. Průměrna siře žily byla 8,5 mm (5-25 mm). Vsechny operace byly provedeny ambulantně v mistnim znecitlivěni s užitim tumescentni anestezie. Vsechny výkony byly provedeny s peroperacni sonografickou kontrolou.Výsledky: Casný uzavěr byl uspěsný u 98,8 % intervenovaných žil. Casna recidiva byla pozorovana u deviti pacientů (15 žilnich segmentů). Vsechny byly uspěsně casně reintervenovany a uzavřeny. Mezi přiciny neuplneho uzavěru patřily zejmena běžně zname rizikove faktory (antikoagulacni terapie, varikoflebitida v anamneze). Nebyla zjistěna korelace s větsim průměrem žily. U sesti pacientů byl pozorovan prolaps trombu do lumen hluboke femoralni žily. Vsechny připady byly uspěsně vyleceny po týdnu lecby nizkomolekularnim heparinem. Byl zaznamenan pouze jeden připad nizkorizikove plicni embolie u pacientky, ktera neuposlechla režimova doporuceni.Zavěr: Endovenozni laserova ablace velke a male safeny a jejich velkých větvi v lecbě symptomatickeho žilniho refluxu je proveditelna, bezpecna a reprodukovatelna metoda. Uzavěr žilnich segmentů nebyl limitovan jejich průměrem ani poctem.

Inferior sinus venosus and two ostium secundum atrial septal defects is possible to treat with three occludersth three occluders

A 73-year-old woman known to have multiple atrial septal defects (mASD) since 2006 rejected cardiac surgery and was referred to our department with signs of right heart failure. Echocardiography demonstrated one defect located in the inferior portion of the atrial septum that led to an overriding inferior vena cava (IVC) – an inferior sinus venosus defect (SVD) and two additional ostium secundum ASDs (ASDII; Figure 1). Furthermore, a significant left-to-right atrial shunt and dilation of the right ventricle were observed.

Impact of coexisting multivessel coronary artery disease on short-term outcomes and long-term survival of patients treated with carotid stenting.

Introduction Systemic atherosclerosis can result in both coronary artery disease (CAD) and carotid artery disease. Recently it has been shown that patients with CAD have a higher incidence of microembolization during carotid artery stenting (CAS), and it has been hypothesized that they could be at higher risk in this intervention. Material and methods We retrospectively evaluated an institutional registry with 437 consecutive patients who underwent coronary angiography and CAS to evaluate their short-term outcomes and long-term survival with regard to the presence of coexisting multivessel coronary artery disease (MVD). Results We performed 220 CAS procedures in MVD patients and 318 CAS procedures in non-MVD patients. The incidence of in-hospital CAS-related adverse events was 2.7% and 2.5% in the MVD and non-MVD groups, respectively (p = 0.88). At 30 days, there was no significant difference between the groups in terms of the number of patients with adverse events (hierarchically death/stroke/myocardial infarction; 8.8% vs. 5.5%; p = 0.18). The median duration of follow-up was 4.23 years. Survival free of all-cause mortality at 1, 3 and 5 years was 90% (95% CI: 86–94%), 79% (95% CI: 73–85%) and 70% (95% CI: 64–77%), and 92% (95% CI: 89–95%), 85% (95% CI: 80–90%) and 76% (95% CI: 70–82%) for the MVD and non-MVD groups (p = 0.02), respectively. Conclusions These results suggest that patients with MVD combined with carotid artery disease are probably not at higher risk of early post-CAS adverse clinical events, but they have significantly worse long-term survival rates.

Intravascular Near-Infrared Spectroscopy: A Possible Tool for Optimizing the Management of Carotid Artery Disease

Stroke is the second most common cause of morbidity and mortality in the Western nations. It is estimated that approximately one-fifth of all strokes or transient ischemic attacks are caused by carotid artery disease. Thus, treatment of carotid artery disease as a mean of stroke prevention is extremely important. Since the introduction of carotid endarterectomy, debate has persisted over the treatment strategy for carotid artery disease. Current recommendations have many potential flaws because they are often based on older trials performed before the introduction of modern pharmacotherapy and are mostly based on the angiographic degree of stenosis, without an emphasis on the pathophysiology of the disease. Most carotid events are caused by rupture or distal embolization of the content of an unstable atherosclerotic plaque with a large lipid pool. Thus, it is plausible that the information regarding the composition of the atherosclerotic plaque could play an important role in deciding on a treatment strategy. In this review article, we provide information about near-infrared spectroscopy, a new invasive imaging modality, which seems to be capable of providing such information.