Comparison of CT acquired valvular calcification scores in hemodialysis vs peritoneal dialysis patients undergoing open heart surgery

Background

Several factors have been identified as independent risk factors for cardiac valvular calcification (CVC), including but not limited to age, inflammatory conditions, loss of calcification inhibitors, and dysregulated bone mineral metabolism. However, data is scarce regarding which dialysis modality portends more severe CVC.

Purpose

Our aim was to compare the degree of valvular calcification in hemodialysis (HD) and peritoneal dialysis (PD) patients prior to open heart surgery (OHS) using a computed CT calcium score.

Methods

Dialysis patients who underwent OHS at our institution from 2009–2019 who had a pre-surgical cardiac CT were grouped according to duration of dialysis modality prior to their surgical date. There were two study cohorts to evaluate outcomes of interest: mitral and aortic calcification. We included the first surgical record per patient for patients undergoing isolated CABG, or CABG+valve surgery (repair or replacement), or valve-only surgery (repair or replacement). To evaluate mitral calcification, we excluded any patients undergoing any mitral valve surgery (repair or replacement). We also excluded patients with a history of mitral valve repair/replacement. To evaluate aortic calcification, we excluded any patients undergoing any aortic valve surgery (repair or replacement). We also excluded patients with a history of aortic valve repair/replacement. Mitral annular and aortic valvular calcification were assessed using the Agatston score. Logistic regression was performed to test for the association of PD and HD cumulative dialysis duration with presence of valvular calcification.

Results

A total of 296 patients met inclusion criteria for at least one of the strata in our study. Of those, 214 met inclusion for the mitral strata, and 166 met criteria for the aortic strata (Table 1). In the logistic regression model for the mitral strata, age and female sex were associated with higher odds of presence of mitral calcification (Figure 1). Cumulative years on PD and cumulative years on HD were not significantly associated with presence of mitral calcification. In the logistic regression model for the aortic strata, age was associated with higher odds of presence of aortic calcification, while female sex was associated with lower odds (Figure 1). Cumulative years on PD and cumulative years on HD were not significantly associated with presence of aortic calcification.

Conclusion

Presence of mitral and aortic calcification for patients undergoing OHS was not significantly associated with cumulative length of PD or HD after adjusting for age and gender, suggesting that there may be more factors at play in the progression of valvular calcification in end stage renal disease patients than what was previously thought.

Funding Acknowledgement

Type of funding sources: None.

Lung Transplant for Patients with COVID-19 Bridged with VV ECMO: Initial Experience

Purpose

During the COVID-19 pandemic, veno-venous Extracorporeal Membrane Oxygenation (VV ECMO) has been used extensively for respiratory failure refractory to conventional mechanical ventilation (MV) and rescue maneuvers. However, the worldwide experience with COVID-19 patients undergoing lung transplant (LTx) with pre-LTx VV ECMO support is limited. Therefore, we sought to report our institution's early experience with COVID-19 patients who underwent LTx after VV ECMO.

Methods

We retrospectively identified 5 COVID-19 patients who underwent LTx after VV ECMO support. Patients were required to have a negative nasopharyngeal swab and a negative bronchoalveolar lavage for COVID-19 prior to LTx listing. We analyzed preoperative and operative characteristics, details of VV ECMO support and early post-transplant outcomes.

Results

The mean age of our cohort was 50 years (range 39-57 years) and all patients were male. Mean recipient BMI was 30 (range 22-37). Mean duration of VV ECMO pre-Ltx was 60 days (range 44-72 days). At the time of the LTx operation, 60% (3/5) of patients were on VV ECMO, 20% (1/5) were on mechanical ventilation (MV), and 20% (1/5) were on supplemental oxygen only. Preoperatively, 80% (4/5) had acute kidney injury and 20% (2/5) were on dialysis. LTx was performed via clamshell approach with intraoperative venoaterial ECMO support in all cases. For 60% (3/5) patients, VV ECMO support was continued after LTx and discontinued on postoperative days 0, 1 and 6, respectively. All-cause mortality was 40% (2/5), related to sepsis and multi-organ failure, and both deaths occurred an average of 115 days post-LTx. Mean length of stay for surviving patients was 59 days (range 22-117). In the first 3 months postop-LTx, grade A2 acute cellular rejection was noted in 2 patients, A1 in 2 patients, and antibody-mediated rejection in 1 patient.

Conclusion

Our early experience with LTx for COVID-19 patients supported with VV ECMO support is notable for 1) prolonged VV-ECMO duration and significant morbidity pre-LTx, and 2) early mortalities related to sepsis and multiple organ failure. These data highlight a uniquely complex patient population that carries high risk of multi-organ failure and other comorbidities dictating careful selection for transplant.

Meta-analysis of computed tomography and magnetic resonance imaging for diagnosing mycotic aneurysms

Background

Mycotic aneurysms are a serious complication of infective endocarditis and bloodstream infection with high mortality and morbidity. Computed tomography (CT) and magnetic resonance (MRI) play major roles in detecting mycotic aneurysms, but their accuracy is not well established warranting this meta-analysis.

Purpose

We aimed to assess the diagnostic performance of CT and MRI for mycotic aneurysms in this meta-analysis.

Methods

Pubmed, Cochrane and Embase were searched from 1 January 1980–30 June 2019 for diagnostic studies reporting both sensitivity and specificity of CT and/or MRI for detecting mycotic aneurysms, and pooled using random effects models and Meta-DiSc 1.4 software.

Results

Amongst 1507 articles searched, 15 studies with 622 scans for 249 mycotic aneurysms included. CT was performed in 13 studies and MRI in 5 studies, looking at aortic and cerebral mycotic aneurysm in 12 and 3 studies respectively. The pooled sensitivities and specificities for all mycotic aneurysms with 95% confidence intervals were for CT 0.82 (0.77–0.87) and 0.93 (0.89–0.95) respectively, and for MRI 0.79 (0.61–0.91) and 0.89 (0.81–0.95) (Figure). CT or MRI had pooled sensitivities and specificities of 0.84 (0.78–0.89) and 0.92 (0.89–0.95) for aortic and 0.71 (0.54–0.85) and 0.90 (0.83–0.95) for cerebral mycotic aneurysms. Heterogeneity and publication bias was observed in some pooled analysis.

Conclusion

CT and MRI had moderately high diagnostic accuracy for mycotic aneurysms. Sensitivity was numerically higher for detecting aortic than cerebral mycotic aneurysms, with similar specificity. Study heterogeneity, publication bias and modest sample size from the literature were important limitations, warranting larger and higher quality studies.

Forrest plots for CT and MRI pooled data

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): National Heart Foundation of New Zealand - Overseas Clinical and Research Fellowship

Veno-venous extracorporeal membrane oxygenation using a double-lumen bi-caval cannula for severe respiratory failure post total artificial heart implantation

We report a unique utilization of a double-lumen, bi-caval Avalon cannula for veno-venous (VV) extracorporeal membrane oxygenation (ECMO) during placement of a total artificial heart (TAH, SynCardia, Tucson, AZ). A 22-year-old female with post-partum cardiomyopathy was rescued on veno-arterial (VA) ECMO because of cardiogenic shock. The inability to wean ECMO necessitated implantation of the TAH as a bridge to transplant. In addition, the patient continued to have respiratory failure and concomitant VV ECMO was planned with the implant. During TAH implantation, the Avalon cannula was placed percutaneously from the right internal jugular vein into the inferior vena cava (IVC) under direct vision while the right atrium was open. During VV ECMO support, adequate flows on both ECMO and TAH were maintained without adverse events. VV ECMO was discontinued, without reopening the chest, once the patient's respiratory failure improved. However, the patient subsequently developed a profound respiratory acidosis and required VV ECMO for CO2 removal. The Avalon cannula was placed in the femoral vein to avoid accessing the internal jugular vein and risking damage to the TAH. The patient's oxygenation eventually improved and the cannula was removed at the bedside. The patient was supported for 22 days on VV ECMO and successfully weaned from the ventilator prior to her orthotropic heart transplantation.