Objective:Ceftazidime/avibactam (CZA) is an essential treatment option for managing infections caused by multidrug-resistant (MDR) Gram-negative (G-) bacteria, including Klebsiella pneumoniae OXA-48 and carbapenem-resistant Pseudomonas aeruginosa. Growing evidence indicates that critically ill intensive care unit (ICU) patients often exhibit altered pharmacokinetics (PK) of CZA, which may compromise the achievement of optimal PK/pharmacodynamic (PD) targets with standard dosing regimens. The primary hypothesis of this study is that continuous infusion (CI) of CZA improves microbiological success compared to intermittent dosing (ID) in critically ill ICU patients with severe infections caused by K. pneumoniae OXA-48 or P. aeruginosa. Methods:This is a single-center, randomized, open-label trial with a 1:1 allocation ratio, conducted at the University Hospital Centre Zagreb, a tertiary care hospital in Croatia. A total of 140 critically ill ICU patients with severe infections due to K. pneumoniae OXA-48 or P. aeruginosa requiring CZA treatment will be randomized to receive either ID of CZA (2 g/0.5 g/8 h over 2 h) or the same total daily dose in CI (6 g/1.5 g over 24 h). The study is powered to demonstrate the superiority of CI over ID of CZA in terms of microbiological success. Outcomes:The primary outcome will be microbiological success rate, chosen as a key indicator of pathogen eradication that is directly influenced by PK/PD target attainment. Secondary outcomes will include clinical success rate, time to symptoms improvement, length of ICU stay, length of hospital stay, all-cause 28-day mortality, pathogen recurrence rate on day 28, time to weaning from mechanical ventilation, cumulative vasoactive-inotropic score, adverse events, and the ratio of ceftazidime plasma concentration to the pathogen's minimum inhibitory concentration (C/MIC). Conclusion:This trial will provide evidence on optimal CZA administration regimen in critically ill ICU patients with severe infections due to MDR G-pathogens. Clinica Trial Registration:clinicaltrials.gov, identifier NCT06811727.

Abstract Funding Acknowledgements None. Background Refractory shock is life-threatening condition characterized by hypotension with mean arterial pressure (MAP) less than 65 mmHg and end-organ dysfunction, despite volume resuscitation and high doses of vasopressors. Mortality rates in refractory shock exceeds 90%. Angiotensin II (Ang II) is a non-catecholamine vasopressor that targets the renin-angiotensin-aldosterone system by agonism of the angiotensin type 1 receptors. Ang II has been studied in settings of vasodilatory shock, however there is paucity of data regarding the usage of Ang II in patients with preexisting heart failure or in patients requiring mechanical circulatory support (MCS), either short term such as venoarterial extracorporeal membrane oxygenation (VA-ECMO) or long term such as left ventricular assist device (LVAD) (1,2). Purpose This report is aimed to analyse baseline characteristics of patients who have received Ang II from the moment it became available in our institution (January 2023). Methods Five patients were included in this retrospective analyses. Demographic, clinical and laboratory parameters as well as hourly changes of vasopressors doses, MAP, lactates, and diuresis were collected and analysed. Results Median age of 5 included patients, 4 of whom were male, was 53 years old (range 18-57). The most common comorbidities were chronic kidney disease (n=3), diabetes mellitus (n=3) and arterial hypertension (n=3), treated with valsartan as chronic therapy. All patients presented with severe shock. 4 patients were on VA-ECMO support, 1 had additionally implanted Impella for left ventricular unloading and 2 had implanted LVAD. All patients had severely reduced left ventricular ejection fraction (median 15%, range 10-25%). In 4 cases vasopressors were initiated due to sepsis and in 1 case during cardiopulmonary resuscitation. Median values prior to administration of Ang II were as following: MAP 51 mmHg (range 41-56 mmHg), lactates 6.7 mmol/L (range 2.4-10.7 mmol/L) and Sequential Organ Failure Assessment (SOFA) score 9 (range 5-11). Four hours following administration of Ang II median MAP was 61 mmHg (range 54-77 mmHg). Patient who ultimately survived had better response to Ang II, with median rise of MAP of 22 mmHg (range 12-22 mmHg). In contrast, patients who ultimately died didn’t respond to Ang II, with rise of MAP of only 2.5 mmHg. Median duration of Ang II administration was 52 h (range 20-96 h). 60% of patients are alive up to the present day. Complete patient data are shown in Table 1. Hourly changes of vasopressor doses and MAP are shown in Figure 1. Conclusion Ang II is an effective vasopressor with rapid effect. This case series suggests that it may be considered as salvage treatment option in patients on MCS with refractory shock. Patients who responded to Ang II had better survival, similar to previous findings. Therefore, Ang II should be considered in earlier phases of shock when maximum doses of vasopressors have not yet been reached.

Abstract Background and aim Diabetes mellitus (DM) is related to higher rates of complications after coronary revascularization.1 The efficiency of drug-coated balloon (DCB) percutaneous coronary intervention (PCI) has been shown for in-stent restenosis (ISR) and native small-vessel disease, however data on outcomes in DM is scarce. 2 The aim is to compare the incidence of target lesion restenosis at follow-up (FUP) coronary angiography in patients with and without DM receiving DCB PCI. Material and methods The registry included patients undergoing a DCB PCI at our university hospital centre from February 2011 to January 2022 (n=645). Patient demographics, comorbidities, pharmacotherapy, as well as data on the initial and FUP coronary angiography/PCI was collected. An FUP angiography was performed in 50% of patients (n=317), with a median FUP of 6 (interquartile range 3-17) months. Results Data is shown in Table 1. The cohort was 75% male, mean age 65 ± 10 years. DM was present in 35% (n=223) of patients, equally in both sexes, and was associated with a history of myocardial infarction, PCI, coronary artery bypass grafting, stroke; as well as arterial hypertension, and renal insufficiency. No age difference was noted between groups. At initial PCI, more DM patients had multivessel coronary disease and ISR as the indication for DCB (DM vs non-DM: 41% vs 31%, p=0.023). After DCB, no group difference was noted in regards to the need for a bail-out PCI. FUP was performed in an equal percentage of patients in both groups (54% vs 48%, p=0.181), with no differences seen in the incidence of restenosis (17% vs. 18%, p=0.879), the need for target lesion PCI (14% vs. 13%, p=0.863), or the use of anti-anginal drugs. Conclusion The findings of our single-centre analysis show that although DM is related to more advanced comorbidities it does not increase the risk of target lesion restenosis after DCB PCI. DCB PCI should be considered as a therapeutic option in candidate patients regardless of DM status.Comparison between diabetic and non diab

Background: Ventricular tachycardia (VT) commonly occurs in patients with structural heart disease, either of ischemic or non-ischemic nature.Treatment options include various antiarrhythmic drugs (AADs) and implantable cardioverter-defibrillators (ICDs).When AADs fail, radiofrequency (RF) catheter ablation is a valuable treatment option for patients with recurrent VT. 1 This single-center ten-year retrospective study aimed to assess acute and chronic success rates of RF catheter ablation and to identify predictors of VT recurrence and patient survival.

Background: Infective endocarditis (IE) remains major cause of morbidity and mortality in adult congenital heart disease (ACHD). Limited data exists on ACHD with IE in Central and South-Eastern European (CESEE) countries. The aim of this study is to characterize contemporary management and assess outcomes of ACHD with IE in CESEE region.Methods: Data on ACHD patients with IE from 9 tertiary centres in 9 different CESEE countries between 2015 and 2020 was included. Baseline demographics, clinical presentation, indication for surgery, outcomes, hospital and all-cause-1-year mortality were studied.Results: A total of 295 ACHD patients (mean age 40 +/- 14 years) with IE were included. Median time from symptoms onset to establishing diagnosis was 25 (11-59) days. The majority of patients (203, 68.8%) received previous empiric oral antibiotic therapy. The highest incidence of IE was observed on native and left sided valves, 194(65.8%) and 204(69.2%), respectively. More than half had a vegetation size >= 10 mm (164, 55.6%); overall 138 (46.8%) had valve complications and 119 (40.3%) had heart failure. In-hospital mortality was 26 (8.8%). Conclusion: There is clear delay in establishing IE diagnosis amongst ACHD patients in CESEE countries. Adequate diagnosis is hampered by common prescription of empiric antibiotics before establishing formal diagnosis. Hence, patients commonly present with associated complications requiring surgery. Hospital treatment and survival are, nevertheless, comparable to other Western European countries. Improved awareness and education of patients and medical profession regarding IE preventive measures, risks, signs, and symptoms are urgently needed. Empiric antibiotic prescription before blood cultures are taken must be omitted.

Aim To assess whether the number of patients with a car-diac chief complaint and their characteristics differed be-tween before and after two major earthquakes that struck Croatia in 2020.Methods We collected data on all visits of patients with a cardiac chief complaint examined in the emergency de-partments of six hospitals nearest to the epicenters. Pa-tients seen during the 7 days before the earthquake were compared with those seen on the day and during the 6 days after the earthquake.Results Patients seen after the earthquake were young-er (68 [59-79] vs 72.5 [65-80]; P < 0.001) and less frequently had cardiovascular disease (32.9% vs 42.8%; P < 0.001). This group less frequently had the primary diagnosis of acute myocardial infarction (AMI) (15.6% vs 21.9%; P = 0.005), heart failure (9.3% vs 19.4%; P < 0.001), dysregulated hyper-tension (13.9% vs 19.4%; P = 0.01), but more frequently had non-anginal chest discomfort (28.8% vs 18.0%; P < 0.001). In a subgroup analysis of patients seen in hospitals lo-cated within 20 km from the epicenter, significantly more patients seen after the earthquake compared with those seen before the earthquake presented with AMI (14.5% vs 22.8%; P = 0.028), acute elevation of blood pressure (10% vs 21.8%, P = 0.001), and paroxysmal arrhythmias treated with electrocardioversion (0.9% vs 4.5%, P = 0.022).Conclusion After two moderately strong earthquakes, hospitals within 20 km from the epicenter saw a signifi-cant increase in acute cardiac conditions such as elevated blood pressure, AMI, and cardioverted arrhythmias. Even-tually, these earthquakes had no impact on the outcomes of the studied population.

Abstract Introduction Implantable cardioverter-defibrillators (ICD) are gold-standard therapy for primary prevention (PP) of sudden cardiac death (SCD) in patients with heart failure with reduced ejection fraction (HFrEF). According to relevant guidelines, ICDs should be implanted only after patients have been treated with revascularization procedures and/or optimal medical therapy (OMT) [1]. Due to perceived high risk of SCD and low chance of improvement some patients receive ICDs “too early” in the course of the disease [2]. Purpose To investigate adherence to guidelines in our institution with emphasis on premature ICD implantation and early ICD activation. Methods We analysed all ICDs newly implanted for PP in patients with HFrEF in our institution between 2011 and 2017. Follow-up data was collected from hospital medical records. Results Total number of 307 ICDs were implanted during the analysed interval, 147 (47.9%) in ischemic cardiomyopathy (ICM) and 160 (52.1%) in non-ischemic dilated cardiomyopathy (DCM) patients. Only 57.8% of ICM patients have been treated with OMT at least 3 months before implantation. The proportion was similar in DCM patients (60.0%). However, DCM patients were more commonly implanted at the time of diagnosis (13.8% vs. 0.7% in ICM). It is worth noting that OMT was up-titrated after implantation in 35.2% of patients. In 9 cases patients were treated with ICDs less than 3 months after revascularization procedures or less than 6 weeks after STEMI (6 and 3 cases respectively). Follow-up data revealed that among all the patients who prematurely received an ICD, a device activated to deliver appropriate therapy within 3 months of implantation only in 1 ICM patient (0.7% of ICM patients). That patient had established ICM and was suffering from recurrent unexplained syncopes. One DCM patient with prematurely implanted ICD had early inappropriate ICD activation that was due to supraventricular tachycardia. Early ICD activations were generally uncommon even among patients who were treated according to guidelines (1 ICM and 1 DCM patient). Conclusion Results from our institutional ICD registry show that a significant number of patients with HFrEF received premature ICD implants before being treated with OMT. This is even more common in patients newly diagnosed with DCM. Our follow-up data suggests that early ICD activation is extremely rare in all comers and hardly ever happens in patients who received ICD immediately after diagnosis, revascularization or without 3 months of OMT. This data can help improve our future practice and encourage clinicians to follow relevant guidelines when faced with these important decisions. Funding Acknowledgement Type of funding sources: None.

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Cryoballoon (CB) isolation of pulmonary veins (PVI) has become the standard of care for patients suffering from atrial fibrillation (AF). PVI could be achieved by radiofrequency ablation with 3D mapping technology omitting the use of fluoroscopy, so called "0 fluoro" approach. However, CB still requires radiation use. Minimization of radiation exposure is important both for patients and operators. Purpose We aimed to demonstrate the feasibility of radiation dose reduction in the setting of CB ablation for AF. Methods We have performed a retrospective study on patients that have undergone CB ablation since the beginning of the AF ablation program in our institution. Procedures were performed under conscious sedation. Both femoral veins were punctured and a single introducer was placed in each vein. A single transseptal puncture was performed guided by intracardiac ultrasound and a 28 mm cryoballoon was used. A single 180 seconds freeze strategy was employed. We analyzed 3 groups of 50 consecutive patients. First group (G1) consisted of subjects at the beginning of our AF program in 2015. In that time, we systematically used 3D rotation angiography for left atrium imaging and higher frame rates both for fluoro (4-10 frames per second - (fps)) and cine (7.5-10 fps) modes of diascopy. Second group (G2) consisted of 50 consecutive patients in 2018 when we stopped using rotational angiography and lowered frame rates (fluoro 4-6 fps, cine 4-6 fps). The third group (G3) consisted of the last 50 patients that we performed in 2021 when we stopped using grid for X ray scatter reduction, lowered fluoroscopy to 2-3 fps, and almost completely abandoned the use of cine mode. Results We have analyzed in total 150 patients (73% male, 59.4±12.6 years old), 50 in each group. There was a significant decrease of procedure and fluoroscopy time that could be attributed to growing operators’ experience and abandoning the use of 3D rotational angiography. More importantly, there was a major decrease in radiation doses applied during the course of the study. Recently, we are using only 2% of radiation doses applied in the beginning of our study (Table). Conclusion By following a few relatively simple steps (omitting the preprocedural imaging, removing grid from the X ray detector and using very low frame rates) CB ablation could be performed with ultralow radiation exposure. However, a certain level of experience is required to be able to perform CB ablation with relatively low X ray image quality and without preprocedural imaging of left atrium.