Heparin Dosing During Percutaneous Coronary Intervention and Obesity.

ABSTRACT: Unfractionated heparin is the most common anticoagulant used during percutaneous coronary intervention. Practice guidelines recommend an initial weight-based heparin bolus dose between 70 and 100 U/kg to achieve target activated clotting time (ACT) of 250-300 seconds. The impact of severe obesity on weight-based heparin dosing is not well studied. We performed a retrospective analysis of 424 patients undergoing percutaneous coronary intervention who received heparin for anticoagulation. We collected detailed data on cumulative heparin administration and measured ACT values in this cohort. We performed separate analyses to identify clinical predictors that may affect dose-response curves. There was significant variability in dosing with mean dose of 103.9 ± 32-U/kg heparin administered to achieve target ACT ≥ 250 seconds. Women received higher initial heparin doses when adjusted for weight than men (97.6 ± 31 vs. 89 ± 28 U/kg, P = 0.004), and only 49% of patients achieved ACT ≥ 250 s with the initial recommended heparin bolus dose (70-100 U/kg). Lower heparin dose (U/kg) was required in obese patients to achieve target ACT. In multivariate linear regression analysis with ACT as dependent variable, after inclusion of weight-based dosing for heparin, body mass index was the only significant covariate. In conclusion, there is significant variability in the therapeutic effect of heparin, with a lower weight-adjusted heparin dose required in obese patients.

Cirrhotic cardiomyopathy: Predictors of major adverse cardiac events and assessment of reversibility after liver transplant.

BACKGROUND: Major adverse cardiac events (MACE) are a leading cause of morbidity and mortality after orthotopic liver transplantation (OLT). Cirrhotic cardiomyopathy (CCM), initially described in 2005 and revised in 2019, is a source of MACE in patients after OLT. We sought to identify CCM-related predictors of MACE at one-year follow-up after OLT and assess for reversibility of CCM post-OLT. METHODS: This is a retrospective study of adult patients who underwent OLT between 2009 and 2019. All patients had transthoracic echocardiography pre-and post-OLT. Patients with a left ventricular ejection fraction <50 % pre-OLT were excluded. MACE was defined as death, myocardial infarction, congestive heart failure hospitalization, or cardiac arrest. RESULTS: In total, 131 patients were included in this study, of whom 103 and 23 patients met the 2005 and 2019 criteria, respectively. During the follow-up period, 42 patients had MACE and these patients were more likely to have ascites (p = 0.003), hepatorenal syndrome (p = 0.019), and CCM per 2005 criteria (p = 0.023). There were no significant differences between pre-OLT CCM per 2019 criteria (19 % vs 17 %, p = 0.758) or MELD-Na score (21.24 vs 19.40, p = 0.166) for MACE post-OLT. Per the 2005 criteria, 35 of 103 patients recovered and these patients were less likely to have MACE post-OLT (p = 0.012). Per the 2019 criteria, 13 of 23 patients recovered post-OLT but this low number precluded further statistics. CONCLUSION: The 2005 Montreal criteria for CCM were an independent predictor of MACE at one-year follow-up post-OLT while the 2019 CCC criteria for CCM were not. In addition, the 2005 Montreal criteria were more prevalent when compared to 2019 CCC criteria. Finally, the 2005 Montreal criteria were reversible post-OLT 34 % of the time compared to the 2019 CCC criteria which were reversible 57 % of the time.

Assessment of Vascular and Valvular Calcification Improves Screening for Coronary Artery Disease Before Liver Transplantation.

Coronary artery disease (CAD) is common in patients with cirrhosis who underwent orthotopic liver transplantation (OLT) evaluation and stress echocardiogram (echo) has a low sensitivity in these patients. This study aimed to assess the impact of vascular and valvular calcification on the ability to identify CAD before OLT. We performed a case-control study of 88 patients with and 97 without obstructive CAD who underwent OLT evaluation. All patients had a preoperative stress echo, abdominal computed tomography, and cardiac catheterization. A series of nested logistic regression models of CAD were fit by adding independent variables of vascular (including coronary) calcification, aortic and mitral valve calcification, age, gender, and history of diabetes mellitus requiring insulin to a baseline model of abnormal stress echo. Compared with stress echo alone, identification of the presence or absence of vascular and valvular calcification on routine preoperative computed tomography and echo improved the diagnostic performance for the detection of CAD based on coronary angiogram when combined with stress echo in patients with cirrhosis who underwent OLT evaluation (area under the curve 0.58 vs 0.73, p <0.001), which is even further improved when age, gender, and history of diabetes mellitus requiring insulin are considered (area under the curve 0.58 vs 0.80, p <0.001). Achieving target heart rate (p = 0.92) or rate-pressure product >25,000 (p = 0.63) did not improve the ability of stress echo to identify CAD. In conclusion, the use of abdominal vascular, coronary artery, and valvular calcification, along with stress echo, improves the ability to identify and rule out obstructive CAD before OLT compared with stress echo alone.

Hepatic Ischemia/Reperfusion Injury After Liver Transplantation Is Not Associated with Early Impairment of Left Ventricular Ejection Fraction.

BACKGROUND Early myocardial dysfunction is a known complication following liver transplant. Although hepatic ischemia/reperfusion injury (hIRI) has been shown to cause myocardial injury in rat and porcine models, the clinical association between hIRI and early myocardial dysfunction in humans has not yet been established. We sought to define this relationship through cardiac evaluation via transthoracic echocardiography (TTE) on postoperative day (POD) 1 in adult liver transplant recipients. MATERIAL AND METHODS TTE was performed on POD1 in all liver transplant patients transplanted between January 2020 and April 2021. Hepatic IRI was stratified by serum AST levels on POD1 (none: <200; mild: 200-2000; moderate: 2000-5000; severe: >5000). All patients had pre-transplant TTE as part of the transplant evaluation. RESULTS A total of 173 patients underwent liver transplant (LT) between 2020 and 2021 and had a TTE on POD 1 (median time to echo: 1 day). hIRI was present in 142 (82%) patients (69% mild, 8.6% moderate, 4% severe). Paired analysis between pre-LT and post-LT left ventricular ejection fraction (LVEF) of the entire study population demonstrated no significant decrease following LT (mean difference: -1.376%, P=0.08). There were no significant differences in post-LT LVEF when patients were stratified by severity of hIRI. Three patients (1.7%) had significant post-transplant impairment of LVEF (<35%). None of these patients had significant hIRI. CONCLUSIONS hIRI after liver transplantation is not associated with immediate reduction in LVEF. The pathophysiology of post-LT cardiomyopathy may be driven by extra-hepatic triggers.