Sumita Barua

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) has failed to demonstrate mortality benefit in randomised controlled trials of cardiogenic shock. We aimed to determine whether a novel ‘Hemi-ECMO’ configuration, involving aortic occlusion to isolate the left ventricle from the VA-ECMO circuit, improves cardiac haemodynamics. We utilised a pulsatile biventricular mock circulatory loop with variable contractility to compare standard VA-ECMO with Hemi-ECMO support under left ventricular or biventricular failure conditions. When averaged across all pump speeds, mean left atrial pressure was significantly reduced with Hemi-ECMO compared to VA-ECMO (21.11 ± 1.32 mmHg vs. 26.53 ± 0.87 mmHg, p < 0.001), with more pronounced benefit at higher pump speeds. Aortic ejection increased with Hemi-ECMO at higher pump speeds: 0.14 ± 0.03 vs. 0.00 ± 0.00 L/min (p = 0.002) at 3000 revolutions per minute (RPM). Aortic ejection was greater with Hemi-ECMO in the descending aorta compared to the ascending aorta position (0.27 ± 0.03 L/min vs. 0.17 ± 0.05 L/min, p = 0.015). In conclusion, Hemi-ECMO demonstrates significant haemodynamic advantages in severe cardiogenic shock, including reductions in mean left atrial pressure and increases in aortic ejection, with greater benefits when positioned in the descending aorta. Further in vivo studies are warranted to assess clinical viability.

Background: Acute kidney injury (AKI) in the context of acute decompensated heart failure (ADHF) encompasses a broad spectrum of phenotypes with associated disparate outcomes. We evaluate the impact of ‘ongoing AKI’ on prognosis and cardiorenal outcomes and describe predictors of ‘ongoing AKI’. Methods: A prospective multicentre observational study of patients admitted with ADHF requiring intravenous furosemide was completed, with urinary angiotensinogen (uAGT) measured at baseline. AKI was defined using Kidney Disease Improving Global Outcomes (KDIGO) AKI criteria. AKI recovery status was defined as ‘no AKI’, ‘recovered AKI’ or ‘ongoing AKI’ based on renal function at hospital discharge. Event-free survival analysis was performed to predict death and cardiorenal outcomes at hospital discharge and 6-month follow-up. Multinomial logistic regression was performed to identify predictors of ongoing AKI. Multiclass receiver operator curve analysis was performed to evaluate the relationship between renin-angiotensin system (RAS) blockers and uAGT in predicting ongoing AKI. Results: Among 271 enrolled patients, 121 (44.6%) patients developed AKI, of whom 62 patients had ongoing AKI. Ongoing AKI was associated with increased risk of death (HR 6.89, p<0.001), in-hospital end-stage kidney disease (HR 44.39, p<0.001), 6-month composite of death, transplant, left ventricular assist device and heart failure hospitalisation (HR 3.09, p<0.001), and 6-month composite major adverse kidney events (HR 5.71, p<0.001). Elevated baseline uAGT levels, chronic beta-blocker and thiazide diuretic therapy, and lack of RAS blocker prescription at recruitment were associated with ongoing AKI. While uAGT levels were lower with RAS blocker prescription, in patients with ongoing AKI, uAGT levels were elevated regardless of RAS blocker status. Conclusion: Patients experiencing ongoing AKI during ADHF admission were at increased risk of death and other adverse cardiorenal outcomes. Differential uAGT response in patients receiving RAS blockers with ongoing AKI suggests biomarkers may be helpful in predicting treatment responses and cardiorenal outcomes.

Background: The impact of continuous flow resulting from contemporary left ventricular assist devices (LVAD) on renal vascular physiology is unknown. Renal resistive index (RRI) reflects arterial compliance, as well as renal vascular resistance, contributed by afferent and efferent arteriolar tone, the renal interstitium as well as renal venous pressures.Methods: Prospective, single center study with renal Doppler evaluation at baseline (pre‐implant) and at 3‐months support. Outcomes assessed include need for post‐operative renal replacement therapy (RRT), worsening renal function (WRF) defined as persistent increase from pre‐implant KDIGO chronic kidney disease stage, right ventricular (RV) failure, and survival to transplantation.Results: Pre‐implant RRI did not predict cardiorenal outcomes including right heart failure, need for renal replacement therapy or worsening renal function. Post‐implant RRI was significantly lower than pre‐implant RRI, with a distinct Doppler waveform characteristic of continuous flow. Post‐implant renal end‐diastolic velocity, but not RRI, correlated strongly with LVAD flow (Spearman rho −0.99, p < 0.001), with trend toward correlation with mean arterial pressure (Spearman's rho 0.63, p = 0.129). There was a negative correlation between post‐implant RRI and mean pulmonary artery pressure (Spearman's rho −0.81, p = 0.049), likely driven by elevated pulmonary capillary wedge pressure (Spearman's rho −0.83, p = 0.058).Conclusion: The hemodynamic contributors to RRI in LVAD supported patients are complex. Higher mean pulmonary artery and pulmonary capillary wedge pressures seen in lower RRI may reflect a smaller difference in systolic and diastolic flow. Future simultaneous Doppler assessment of the LVAD outflow graft and RRI may help understand the hemodynamic interactions contributing to this index.

Type 1 cardiorenal syndrome is associated with significant excess morbidity and mortality in patients with severe acute decompensated heart failure. Previous trials of vasoactive drugs and ultrafiltration have not shown superiority over placebo or intravenous diuretics. Pilot data suggest short-term mechanical support devices may support diuresis in the cardiorenal syndrome. We evaluated the intra-aortic balloon pump (IABP) and a novel intra-aortic entrainment pump (IAEP) in a mock circulation loop (MCL) biventricular systolic heart failure model, to assess impact on renal flow and cardiac hemodynamics. Both devices produced similar and only modest increase in renal flow (IABP 3.3% vs. IAEP 4.3%) and cardiac output, with associated reduction in afterload elastance in the MCL. There were minor changes in coronary flow, increase with IABP and minor decrease with IAEP. Differences in device preload and afterload did not impact percentage change in renal flow with IABP therapy, however, there was a trend toward higher percentage flow change with IAEP in response to high baseline renal flow. The IAEP performed best in a smaller aorta and with more superior positioning within the descending aorta. Demonstrated changes in MCL flow during IAEP were of lower magnitude than previous animal studies, possibly due to lack of autoregulation and hormonal responses.

Aims: There is limited data describing major adverse kidney events (MAKE) in patients supported with ventricular assist devices (VAD). We aim to describe the association between MAKE and survival, risk factors for MAKE, and renal trajectory in VAD supported patients. Methods and results: We conducted a single-centre retrospective analysis of consecutive VAD implants between 2010 and 2019. Baseline demographics, biochemistry, and adverse events were collected for the duration of VAD support. MAKE was defined as the first event to occur of sustained drop (>50%) in estimated glomerular filtration rate (eGFR), progression to stage V chronic kidney disease, initiation or continuation of renal replacement therapy beyond implant admission or death on renal replacement therapy at any time. One-hundred and seventy-three patients were included, median age 56.8 years, 18.5% female, INTERMACS profile 1 or 2 in 75.1%. Thirty-seven patients experienced MAKE. On multivariate analysis, post-implant clinical right ventricular failure and the presence of chronic haemolysis, defined by the presence of schistocytes on blood film analysis, were significantly associated with increased risk of MAKE (adjusted odds ratio 9.88, P < 0.001 and adjusted odds ratio 3.33, P = 0.006, respectively). MAKE was associated with reduced survival (hazard ratio 4.80, P < 0.001). Patients who died or experienced MAKE did not demonstrate the expected transient 3-month improvement in eGFR, seen in other cohorts. Conclusions: MAKE significantly impacts survival. In our cohort, MAKE was predicted by post-implant right ventricular failure and chronic haemolysis. The lack of early eGFR improvement on VAD support may indicate higher risk for MAKE.

Background.: Cardiorenal syndrome (CRS) contributes significantly to morbidity and mortality in patients requiring mechanical circulatory support and transplantation. There are no validated markers to predict major adverse kidney events (MAKEs), for which simultaneous heart-kidney transplant (SHKT) could offer improved survival. We evaluate renal histology in predicting MAKEs in transplant-listed patients. Methods.: We identified 18 patients with renal histology consistent with CRS from 655 consecutive heart transplant-listed patients between 2010 and 2019. Biopsies were analyzed for glomerular, tubular, interstitial, and arteriolar changes tallied to give a biopsy chronicity score. The primary outcome, MAKE, was a composite of death, need for renal replacement therapy (RRT), or estimated glomerular filtration rate decline >50%. These were evaluated at 2 time points: before and following the transplant. Secondary outcomes included the individual components of the composite outcomes and the need for short-term RRT following the transplant. Results.: The mean age was 52.3 y, 22% were female. Five patients did not survive to transplant. One patient underwent successful SHKT. MAKE occurred in 8 of 18 before the transplant and in 8 of 13 following the transplant. Neither outcome was predicted by baseline biochemistry. The biopsy chronicity score was significantly higher in patients with MAKE before transplant (4.3 versus 1.7, P = 0.024) and numerically higher in patients requiring short-term RRT following transplant (3.2 versus 0.7, P = 0.075). Contrary to limited previous literature, interstitial fibrosis did not predict any outcome, whereas tubular atrophy and arteriosclerosis were associated with MAKE before transplant. Conclusions.: A higher biopsy chronicity score was associated with adverse kidney endpoints, raising its potential utility over standard biochemistry in considering SHKT referral.

Background : We present a 23-year-old Nepalese migrant with mycobacterial tuberculosis (TB) pericarditis manifesting as effusive constrictive disease and subsequent rapid progression to constrictive pericarditis resulting from bulky granulomatous disease. Case summary : Following initial presumptive diagnosis of TB pericarditis based on presence of moderate pericardial effusion and positive polymerase chain reaction on concurrent pleural aspirate, the patient was managed with standard empiric therapy. Despite treatment, he developed progressive heart failure with New York Heart Association (NYHA) class III symptoms and had confirmation of constrictive physiology on simultaneous left and right heart catheterization. He underwent pericardiectomy 4 months after his initial diagnosis, with debridement of large necrotizing granulomas and an associated immediate improvement clinical improvement. He remains well at 6-month follow-up with no residual heart failure symptoms off diuretic therapy. Discussion : Tuberculous pericarditis accounts for 1–2% of presentations with TB infection, with progression to constrictive pericarditis in between 17 and 40% of cases. To date, pericardiectomy remains mainstay of treatment for constriction, albeit with high perioperative risk. In combination with anti-tuberculous therapy, prednisone and pericardiocentesis may reduce risk of progression to constriction, however, neither have shown mortality benefit. Our patient continued to progress, despite medical therapy and proceeded to pericardiectomy only 4 months after his initial diagnosis, with rapid improvement in symptoms, demonstrating the importance of close monitoring and revision of management strategy in these patients.

Background: Primary percutaneous coronary intervention (PCI) is the cornerstone of management for ST-elevation myocardial infarction (STEMI). However, large intracoronary thrombus burden complicates up to 70% of STEMI cases. Adjunct therapies described to address intracoronary thrombus include manual and mechanical thrombectomy, use of distal protection device and intracoronary anti-thrombotic therapies. Case summary: This series demonstrates the use of intracoronary thrombolysis in the setting of large coronary thrombus, bifurcation lesions with vessel size mismatch, diffuse thrombosis without underlying plaque rupture, and improving coronary flow to allow vessel wiring and proceeding to definitive revascularization. Discussion: Larger intracoronary thrombus burden correlates with greater infarct size, distal embolization, and the associated no-reflow phenomena, and propagates stent thrombosis, with subsequent increase in mortality and major adverse cardiac events. Intracoronary thrombolysis may provide useful adjunct therapy in highly selected STEMI cases to reduce intracoronary thrombus and facilitate revascularization.