Background. Solid organ transplant recipients (SOTRs) are at heightened risk for cardiovascular implantable electronic device-related complications, particularly infection, because of chronic immunosuppression and comorbidities. Although leadless pacemakers (LPs) reduce infection risk by eliminating transvenous leads and generator pockets, adoption in SOTRs has remained limited, largely because earlier systems were restricted to single-chamber ventricular pacing and lacked physiologic atrioventricular synchrony. The helix-fixation Aveir LP platform enables atrial, ventricular, and dual-chamber leadless pacing, but clinical experience in transplant recipients remains limited. Methods. We conducted a retrospective, multisite analysis across an integrated health system, identifying all adult SOTRs who underwent Aveir LP implantation between January 2022 and October 2025. Clinical characteristics, transplant details, pacing indications, device configuration, procedural outcomes, and follow-up data were collected. Primary outcomes included procedural success, complications, and device-related infection. Secondary outcomes included pacing performance, need for system revision or upgrade, and early device durability. Results. Thirteen SOTRs (mean age 64 ± 15 y; 15% female) underwent Aveir LP implantation, including atrial (n = 4), ventricular (n = 5), and dual-chamber (n = 4) systems. Transplanted organs included heart (46%), lung (31%), kidney (38%), and liver (15%), with 31% having multiple organ transplants. Over half of patients were critically ill at implantation, and 46% were dialysis-dependent, representing a high-risk cohort. All procedures were acutely successful with no intraprocedural complications. During a median follow-up of 258 d (interquartile range, 216–641 d), no device-related infections occurred. Electrical performance remained stable, with 1 atrial device replacement at 2.5 y for elevated capture thresholds. Conclusions. In a high-risk population of SOTRs, atrial and atrioventricular synchronous leadless pacing using the Aveir platform was feasible, achieved high acute procedural success, and demonstrated favorable early safety signals, including absence of device-related infection over available follow-up. Larger studies with longer-term follow-up are needed to define durability and long-term outcomes.
Diuretic resistance and associated mortality outcomes among patients in the cardiac intensive care unit
Abstract Background Diuretic resistance (DR) is the failure to achieve adequate natriuresis despite high diuretic doses, reflecting a state of low diuretic efficiency (DE). In heart failure (HF) and general intensive care cohorts, low DE and the presence of DR have been associated with adverse outcomes, including increased risk of rehospitalization and mortality (1-3). Quantitative data, however, remains limited in patients admitted to the cardiac intensive care unit (CICU) – a population characterized by cardiac critical illnesses and substantial cardiorenal interactions. Purpose The aim of this study is to investigate and characterize the association between DR and associated mortality outcomes in CICU patients. Methods This retrospective cohort study included adult CICU patients (2007-2018) who received loop diuretics on day 1 of admission. Patients with a stay <1 day or oliguria [<400mL urine output (UOP) total] were excluded. DR was defined as <500mL of UOP per 40mg oral furosemide equivalent (FSE). Acute kidney injury (AKI) was defined per KDIGO guidelines. Primary outcome was all-cause in-hospital mortality (including CICU deaths), and secondary outcome was all-cause 1-year mortality. In-hospital mortality predictors were evaluated using logistic regression and 1-year mortality predictors by Cox proportional-hazards models. 1-year survival was assessed using Kaplan-Meier curves. Multivariable models were adjusted for known confounders. Results 3,229 total patients were included. Median age was 71.2 (61.2, 80.7) years and 41.3% were female. Admission diagnoses included HF exacerbation (79.9%), acute coronary syndrome (34.5%), and respiratory failure (38.9%), among others. 1,098 (34.0%) patients met DR criterion; they had higher severity of illness scores, more comorbidities (including HF, diabetes mellitus, lung disease, and chronic kidney disease, p<0.001), and greater laboratory derangements. On admission, 23.6% patients had AKI, of which 54.3% patients met DR criterion. During hospitalization, 56.0% patients had AKI; those with DR had higher prevalence and severity of AKI (unadjusted OR 3.55 [3.02-4.17], p<0.001). Overall in-hospital mortality was 9.8% (including 5.2% in the CICU). In patients with DR, in-hospital mortality was 17.0% (9.7% in the CICU). Notably, 59.4% of all in-hospital deaths occurred in patients with DR. DR was independently associated with higher in-hospital (adjusted OR 2.00 [1.51-2.64], p<0.001) and 1-year (adjusted HR 1.64 [1.44-1.88], p<0.001) mortality. Patients with DR had higher mortality in each AKI stage (Figure 1), and patients with concomitant DR and AKI had the highest risk of 1-year mortality (Figure 2). Conclusion DR, defined by our easily applicable threshold, emerged as a powerful, independent predictor of adverse outcomes and was associated with substantially higher mortality, demonstrating potential as a valuable risk stratifying tool.
Minimum mean arterial pressure and in-hospital mortality in the cardiac intensive care unit: an admission diagnosis subgroup analysis
Abstract Background Hypotension is a recognized predictor of mortality in the cardiac intensive care unit (CICU) (1-3). Although prior studies link lower mean/averaged mean arterial pressure (MAP) to adverse outcomes, they highlight the need for dedicated research on the minimum MAP (mMAP), as mean data may fail to capture the clinical significance of brief, severe hypotensive episodes. Purpose This study aims to investigate the mortality outcomes associated with the mMAP within the first 24 hours of CICU admission and further stratified according to admission diagnoses. Methods This retrospective cohort study included adult CICU patients with available mMAP data (2007-2018). Patient data were extracted including admission diagnoses, critical care therapies (hemodynamic/ventilatory support, continuous renal replacement therapy), comorbidities, vital signs, lab values, and mortality outcomes. MAP was measured either invasively (arterial catheter) or non-invasively (blood pressure cuff). Primary exposure was mMAP, defined as the lowest recorded MAP in first 24 hours of CICU admission. Primary outcome was in-hospital mortality analyzed using logistic regression, before and after multivariable adjustment. Mortality outcomes were analyzed according to mMAP and stratified by admission diagnoses (not mutually exclusive). Results 11,930 patients were included. Median age was 69.4 (58.1, 79.2) years and 37.7% were female. Admission diagnoses included heart failure (48.7%), acute coronary syndrome (42.7%), shock (14.9%), and cardiac arrest (11.8%). Critical care therapies were used in 58.5%. Median mMAP was 54 (47, 62) mmHg. 1080 (9.1%) patients died during hospitalization, including 672 (5.6%) in the CICU. Median mMAP was lower in patients who died in the CICU (46 vs. 55 mmHg, p<0.001) and during the hospitalization (47 vs. 55 mmHg, p<0.001). In the overall cohort, the lowest mortality was at mMAP of 71-75 mmHg. Patients with lower mMAP had higher mortality across admission diagnosis subgroups (Fig1). The mMAP associated with the nadir mortality was slightly higher for acute coronary syndrome or cardiac arrest patients (66-70 mmHg) than for heart failure or cardiogenic shock patients (61-65 mmHg) (Fig2). Each 5 mmHg increase in mMAP was associated with lower in-hospital mortality in patients with (unadj OR 0.81 [0.79-0.84], AUC 0.64) and without (unadj OR 0.76 [0.71-0.82], AUC 0.67) critical care therapies. Conclusion Our findings re-affirm that hypotension is a significant predictor of mortality, consistent across all admission diagnoses. Notably, the mMAP range associated with the lowest in-hospital mortality was slightly lower for patients with circulatory failure (heart failure or cardiogenic shock) compared to those with acute coronary syndromes or cardiac arrest. This difference may represent an optimal balance between maintaining perfusion and preventing excessive afterload in the setting of circulatory failure, but further investigation is required.1) Mortality Per mMAP & Admission Diag 2) Nadir Mortality Point