Postoperative Inotropic Requirement Research Articles

Primary Graft Dysfunction in Heart Transplant Recipients-Risk Factors and Longitudinal Outcomes.

Before the 33rd Annual International Society for Heart and Lung Transplantation conference, there was significant intercenter variability in definitions of primary graft dysfunction (PGD). The incidence, risk factors, and outcomes of consensus-defined PGD warrant further investigation. We retrospectively examined 448 adult cardiac transplant recipients at our institution from 2005 to 2017. Patient and procedural characteristics were compared between PGD cases and controls. Multivariable logistic regression was used to model PGD and immediate postoperative high-inotrope requirement for hypothesized risk factors. Patients were followed for a mean 5.3 years to determine longitudinal mortality. The incidence of PGD was 16.5%. No significant differences were found with respect to age, sex, race, body mass index, predicted heart mass mismatch, pretransplant amiodarone therapy, or pretransplant mechanical circulatory support (MCS) between recipients with PGD versus no PGD. Each 10 minute increase in ischemic time was associated with 5% greater odds of PGD (OR = 1.05 [95% CI, 1.00-1.10]; p = 0.049). Pretransplant MCS, predicted heart mass mismatch ≥30%, and pretransplant amiodarone therapy were associated with high-immediate postoperative inotropic requirement. The 30 day, 1 year, and 5 year mortality for patients with PGD were 28.4%, 38.0%, and 45.8%, respectively, compared with 1.9%, 7.1%, and 21.5% for those without PGD (log-rank, p < 0.0001). PGD heralded high 30 day, 1 year, and 5 year mortality. Pretransplant MCS, predicted heart mass mismatch, and amiodarone exposure were associated with high-inotrope requirement, while prolonged ischemic time and multiple perioperative transfusions were associated with consensus-defined PGD, which may have important clinical implications under the revised United Network for Organ Sharing allocation system.

The Effects of Amino Acids Enriched Del Nido Cardioplegia on Myocardial Leucocyte Accumulation and Ventricular Functions in Patients Undergoing Coronary Artery Bypass Grafting Surgery.

One of the main sources of ischemia/reperfusion injury (IRI) and release of free oxygen radicals (FORs) during extracorporeal circulation (ECC) during cardiac surgery is neutrophils. In this study, we investigated the potential effects of our modification of del Nido cardioplegia (mDNC) (amino acids enriched del Nido cardioplegia) on myocardial polymorphonuclear leucocyte (PMNL) accumulation. We also compared the effects of our mDND and classical del Nido cardiplegia (cDNC) on ventricular contractile functions in coronary artery bypass grafting (CABG) surgery. Our study included 100 isolated CABG patients with similar characteristics, including age, gender, preoperative medications, diabetes, hypertension, and left ventricular ejection fraction (LVEF). The patients were divided into two groups. Amino acids supplemented del Nido cardioplegia (L-aspartate and L-glutamate at a dose of 13 milimol/L) in 50 patients (study group, G1). In the remaining 50 patients, we used a classical del Nido cardioplegic solution (cDNC) (control group, G2). Myocardial Tru-Cut biopsy from the right ventricle was taken before the institution of ECC and after weaning from ECC in all patients. Cardiac troponine-I (cTn-I), tumor necrosis factor-alpha (TNF-Alpha), Pro-Brain Natriuretic Peptide (Pro-BNP), and lactate levels were measured pre- and postoperatively. Invasive monitoring was performed to provide the left ventricular functions in both groups in the operating room and noted by a blinded anaesthesiologist. Five patients died post-surgery (5%) (two from SG and three from CG (P = .67), due to low cardiac output syndrome or multiorgan failure. At the postoperative period, cardiac output (CO) and stroke volume index (SVI) was higher in mDNC (mean ± SDS; 32.1 ± 7 versus 22.2 ± 6.9 mL/min/m² (P < .001). CI was significantly higher in mDNC after surgery (3.10 ± 0.76 versus 2.40 ± 0.30L/min/m² (P = .002). Ten patients (20%) in mDNC and 16 patients (32%) in cDNC required inotropic support (P < .001). The postoperative inotropic requirement was less in mDNC (6.1 ± 1.8 mg/kg versus 9.2 ± 1.9 mg/kg, P < .004). Blood gas analyses from the coronary sinus showed that myocardial acidosis was more severe in the control group [pH (0.10 ± 0.09 versus 0.054 ± 0.001; P = .34)]. Blood lactate levels were significantly high in the control group (1.01 ± 0.007 mmol/L versus 1.92 ± 0.35 mmol/L) (P = .22). No difference was found when compared with cardioplegia volume in the mDNC and cDNC groups (mDNC= 990.00 ± 385 mL in DNC = 960 ± 240 mL, P = .070). An aortic cross-clamp time in the mDNC and cDNC groups were 88.4 ± 8.9 min, and 93 ± 11 min, (P = .76), but cardiopulmonary bypass time was significantly low in mDNC (mDNC = 98.3 ± 22.5 min, DNC = 126 ± 19.5 min, P = .0020). TNF-Alpha and Pro-BNP levels in patients received mDNC were significantly low (P = .022). Postoperative cardiac enzyme levels (creatine kinase-MB and high sensitive troponin-I) were significantly low in the mDNC group (P = .0034). Myocardial biopsy results showed that myocardial PMNL accumulation was significantly high in the control group (P = .001). The amount of inotropic agent use was significantly high in the control group (P = .003). After weaning from ECC, the left ventricular stroke work index (LVSWI), cardiac index (CI), and heart rate (HR) were significantly high in the study group (P = .032; P = .002; P = .01). Postoperative blood and blood products requirements were significantly low in the mDNC group (P = .002). At pre-discharge echocardiography, the mDNC group demonstrated significantly higher ventricular ejection fraction (37.9 ± 4.3% and 29.7 ± 3.8%, respectively (P = .003). Our study findings show that glutamate-aspartate supplemented del Nido cardioplegia significantly decrease myocardial PMNL accumulation with reduced release of biochemical markers, including cardiac troponin-I, TNF-alpha, and Pro-Bnp. Our study results demonstrated that amino acids supplementation in del Nido cardioplegia has some advantages in CABG patients, including the decrease of perioperative myocardial infarction and increase significantly the left ventricular functions including ventricular SVI and CI.

Tricuspid annular plane systolic excursion is correlated with poor outcome in surgery for rheumatic heart valvular disease.

BACKGROUNDRight ventricular (RV) function is a major determinant of clinical outcome, but its function indices have not been studied well in surgery for rheumatic valvular heart disease. The aim of this study was to determine the correlation of tricuspid annular plane systolic excursion (TAPSE) with outcome of rheumatic heart valve surgery.METHODSA prospective comparative study was conducted including 100 eligible patients who were divided into two groups based on RV function as assessed by TAPSE measured by two-dimensional (2D) echocardiography preoperatively. Those with TAPSE less than 15 mm were included in group 1 and those with TAPSE of 15 or more were included in group 2.RESULTS50 patients were included in group 1 and 50 patients in group 2. Mean age of the patients was 56.78 ± 15.21 years in group 1 and 54.46 ± 15.03 years in group 2 (P = 0.444). 34 (34%) patients underwent aortic valve replacement (AVR), 35 (35%) underwent both aortic and mitral valves replacement, and 31 (31%) ones had mitral valve replacement (MVR). A significant difference was found between the duration of ventilation (5.15 ± 2.80 hours in group 1 vs. 3.72 ± 2.71 hours in group 2, P = 0.001), postoperative inotropic requirement [more than 24 hours in 18 (36%) patients in group 1 vs. 7 (14%) patients in group 2, P = 0.003], total intensive care unit (ICU) stay (8.92 ± 3.62 days in group 1 vs. 5.20 ± 2.06 days in group 2, P = 0.001), and mortality [7 (14%) in group 1 vs. 2 (4%) in group 2, P = 0.038].CONCLUSIONTAPSE less than 15 mm in patients undergoing surgical correction for rheumatic valvular heart disease leads to poor outcomes. These patients need special attention perioperatively.

Efficacy of Perioperative Oral Triiodothyronine Replacement Therapy in Patients Undergoing Off-Pump Coronary Artery Bypass Grafting

The aim of this study was to assess the effects of oral triiodothyronine (T3) therapy on postoperative thyroid hormone concentrations, hemodynamic variables, and outcomes. A prospective, randomized, controlled, double-blind study. Cardiac operating room at a single institution. One hundred patients undergoing elective off-pump coronary artery bypass graft surgery. Patients received either 20 μg of oral T3 or placebo every 12 hours starting 20 minutes before anesthetic induction, for a total of 4 doses. Plasma concentrations of thyroid hormones were measured serially before surgery, upon arrival in the intensive care unit, and 12, 24, and 36 hours after surgery. Hemodynamic variables also were recorded serially. Postoperative inotrope requirement and major morbidity endpoints were assessed. Serum T3 concentrations were significantly higher with fewer patients having T3 concentrations below the normal range in the T3 group than the placebo group throughout the postoperative period. Hemodynamic variables, postoperative inotrope requirement, and outcome variables showed no differences between the groups. Oral T3 therapy significantly attenuated the postoperative decline in T3 concentrations in patients undergoing off-pump coronary artery bypass graft surgery. The lack of apparent clinical benefit merits further investigations in patients with reduced cardiac performance.

Biopsy Proven Liver Fibrosis and Outcomes in Patients Supported with a Continuous-Flow Left Ventricular Assist Device

Purpose It is not clear whether patients with biopsy proven liver fibrosis have worse outcomes following continuous-flow left ventricular assist device (CF LVAD) implantation. Methods and Materials We retrospectively reviewed all patients in our institution that had a liver biopsy prior to implantation of a CF LVAD. Continuous variables were analyzed with Student’s T-test and categorical variables were analyzed with Fischer’s Exact test. Results From June 2006 to August 2012, there were 14 patients that had a liver biopsy prior to CF LVAD implant. The mean age of patients was 55±10 years, 87% were male, and 47% had ischemic cardiomyopathy. Indications for CF LVAD implant were destination therapy (n=5; 36%), bridge to transplant (n=8; 57%) and bridge to decision (n=1; 7%). The patients were divided into two groups: those with liver fibrosis grade 0 to 1 (Group A, n=5) and those with liver fibrosis grade >1 (Group B, n=9). Baseline demographics were similar between the two groups. There were no significant differences in post-operative renal failure requiring dialysis (p>0.99), reoperation for bleeding (p=0.36), requirement of inotropes>14 days post LVAD implant (p=0.5) or post operative hospital length of stay (LOS) (p=0.72). No patients in either group required RVAD implantation. Post LVAD implant survival was 100% in both groups at 30 days and was 100% and 78% at 1 year for group A and B respectively (p=0.5). Conclusions In this single center retrospective review, patients with liver biopsy proven > stage 1 fibrosis have similar outcomes in terms of short and mid-term survival, need for dialysis, reoperation for bleeding, post-operative inotrope requirement and LOS compared to those with zero or low grade liver fibrosis. No patients in either group required RVAD support. These findings may have important implications in the selection of LVAD candidates with liver dysfunction.

Vitamin D Status in Neonates Undergoing Cardiac Operations: Relationship to Cardiopulmonary Bypass and Association with Outcomes

To determine the incidence of vitamin D deficiency in neonates with congenital heart disease and whether differences exist by race. In addition, we determined the effect of cardiopulmonary bypass on vitamin D levels and explored associations between 25-hydroxyvitamin D [25(OH)D] levels and postoperative outcomes. We performed a secondary analysis of a prospective randomized controlled trial in 70 neonates undergoing cardiac surgery. The neonates' 25(OH)D levels were measured in the operating room before skin incision (baseline), at the cessation of cardiopulmonary bypass, and at 24 hours postoperatively. Associations between these levels and clinical outcomes were explored. Vitamin D deficiency was defined as a 25(OH)D level <20 ng/mL. Vitamin D deficiency was present in 84% (59/70); concentrations in African Americans (n=20) were significantly lower than those of Caucasian/other race/ethnicity (n=50) (10.2±4.2 vs 16.0±5.6 ng/mL, P<.0001). The 24-hour postoperative 25(OH)D levels were not different from baseline and correlated with a reduced postoperative inotropic requirement (r=-0.316, P=.008). Vitamin D deficiency is prevalent in neonates with congenital cardiac defects, and lower postoperative 25(OH)D levels are associated with the need for increased inotropic support in neonates undergoing cardiac operations. These findings support that vitamin D deficiency may play a role in myocardial injury and postoperative recovery and warrants further investigation.

Letters and comments

Thompson AR, Peters N, Lovegrove RE et al. Cardiopulmonary exercise testing provides a predictive tool for early and late outcomes in abdominal aortic aneurysm patients. Ann R Coll Surg Engl 2011; 93: 474–481.

Cardiopulmonary exercise testing provides a predictive tool for early and late outcomes in abdominal aortic aneurysm patients

The aim of this study was to determine if cardiopulmonary exercise testing (CPET) predicts 30-day and mid-term outcomes when assessing suitability for abdominal aortic aneurysm (AAA) repair. Since July 2006 consecutive patients from a single centre identified with a large (≥5.5 cm) AAA were sent for CPET. Follow-up was completed on 1 August 2009. Univariate logistical regression was used to compare CPET parameters with the Detsky score, the Acute Physiology and Chronic Health Evaluation (APACHE) II score and the Vascular Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (VPOSSUM) in predicting predefined early and late outcome measures. Full data were available for 102 patients (93% male, median age: 75 years, interquartile range (IQR): 70-80 years, median follow up: 28 months, IQR: 18-33 months). Ventilatory equivalents for oxygen and APACHE II predicted postoperative inotrope requirement (p=0.018 and p=0.019 respectively). The Detsky score predicted the length of stay in the intensive care unit (p=0.008). Mid-term (30-month) survival was predicted by the anaerobic threshold (p=0.02). CPET provided the only means in this study of predicting both 30-day outcome and 30-month mortality. CPET could therefore become an increasingly important tool in determining the optimum management for AAA patients.

A Propensity Adjusted Comparison of Mitral Valve Repair Versus Replacement in Patients with Severe LV Dysfunction

Objective: The optimal mitral valve (MV) procedure for patients undergoing CABG with functional mitral regurgitation (MR) is unknown. We examined our experience with MV repair vs. replacement in patients (pts) with functional MR and ejection fraction (EF) <35%. Methods: We reviewed pts with EF<35% who underwent CABG with mitral ring annuloplasty repair vs. chordal sparing replacement from 1995–2006. We assessed short and mid-term outcomes including postoperative inotrope requirement, cardiac performance, mortality and recurrence of MR in a propensity adjusted multivariable logistic regression model. Results: Of 93 pts meeting inclusion criteria, 63 had MV repair and 30 had replacement. Repair and replacement patients were matched for age (63y vs. 65y, p=0.6) and preoperative EF (25% vs 28%, p=0.8). Propensity scores predicted repair accurately and refect underlying differences in patient characteristics (0.87 vs 0.28, repair vs replacement, p<0.001, ROC 0.94) Replacement patients had longer postoperative length of stay (25 vs. 18 days, p=0.05) Inotrope requirements (first 48 hours) were not different between groups nor was 24 hour postoperative cardiac index (CI) (2.7 vs 2.5, p=0.5).Thirty-day mortality was 11% (7/63) and 10% (3/30) for the repair and replacement groups, respectively (p=1.0) Actuarial 1 and 5 year survival was 86% and 63% for the repair group and 73% and 50% for the replacement group (p=0.23).The odds ratio of death was 0.8 for repair on propensity adjusted regression (p=0.7). Importantly, 6 of 63 patients (11%) undergoing mitral repair demonstrated moderate or severe MR on follow-up echocardiograms (mean follow-up 11 months). Conclusion: Although most surgeons prefer MV repair for functional MR, CABG with concomitant MV replacement in patients with severe LV dysfunction has equivalent perioperative results. There is no difference in short term inotrope requirements, CI, or survival. Recurrent MR remains a clinical problem in patients undergoing MV repair.

Randomized Controlled Trial of the Effects of Remote Ischemic Preconditioning on Children Undergoing Cardiac Surgery: First Clinical Application in Humans

We conducted a randomized controlled trial of the effects of remote ischemic preconditioning (RIPC) in children undergoing repair of congenital heart defects. Remote ischemic preconditioning reduces injury caused by ischemia-reperfusion in distant organs. Cardiopulmonary bypass (CPB) is associated with multi-system injury. We hypothesized that RIPC would modulate injury induced by CPB. Children undergoing repair of congenital heart defects were randomized to RIPC or control treatment. Remote ischemic preconditioning was induced by four 5-min cycles of lower limb ischemia and reperfusion using a blood pressure cuff. Measurements of lung mechanics, cytokines, and troponin I were made pre- and postoperatively. Thirty-seven patients were studied. There were 20 control patients and 17 patients in the RIPC group. The mean age and weight of the RIPC and control patients were not different (0.9 +/- 0.9 years vs. 2.2 +/- 3.4 years, p = 0.4; and 6.9 +/- 2.9 kg vs. 11.5 +/- 10 kg, p = 0.06). Bypass and cross-clamp times were not different (80 +/- 24 min vs. 88 +/- 25 min, p = 0.3; and 55 +/- 13 min vs. 59 +/- 13 min, p = 0.4). Levels of troponin I postoperatively were greater in the control patients compared with the RIPC group (p = 0.04), indicating greater myocardial injury in control patients. Postoperative inotropic requirement was greater in the control patients compared with RIPC patients at both 3 and 6 h (7.9 +/- 4.7 vs. 10.9 +/- 3.2, p = 0.04; and 7.3 +/- 4.9 vs. 10.8 +/- 3.9, p = 0.03, respectively). The RIPC group had significantly lower airway resistance at 6 h postoperatively (p = 0.009). This study demonstrates the myocardial protective effects of RIPC using a simple noninvasive technique of four 5-min cycles of lower limb ischemia and reperfusion. These novel data support the need for a larger study of RIPC in patients undergoing cardiac surgery.

Predictors of gastrointestinal complications after conventional and beating heart coronary surgery

Gastrointestinal complications after cardiac surgery remain a significant problem despite improvements in pre-operative, operative and post-operative care. The pathophysiology is uncertain, and their prevention remains suboptimal. This prospective, randomised study was designed to define the role of cardiopulmonary bypass (CPB) and cardioplegic arrest in the pathogenesis of gastrointestinal complications following coronary artery surgery. Three hundred patients were prospectively randomised to (1) on-pump conventional coronary artery surgery [150 patients, 114 men, mean age 64 (45-75 years)] with mild hypothermic (32c) CPB and cardioplegic arrest of the heart or (2) off-pump surgery [150 patients, 113 men, mean age 64 (38-66) years] on the beating heart. The association of perioperative factors with gastrointestinal complications was investigated by univariate analysis. Significant variables were then included into a stepwise logistic regression model to ascertain their independent influence on the occurrence of gastrointestinal complications. There were no significant baseline differences between the groups. Eleven patients in the on-pump group and one patient in the off-pump group had post-operative gastrointestinal complications. Univariate analysis showed that CPB inclusive of cardioplegic arrest, left ventricular ejection fraction <50%, emergency surgery, prolonged aortic cross clamp and CPB time, post-operative low cardiac output syndrome, post-operative inotropic requirement, new onset atrial fibrillation (AF), excessive post-operative blood loss and redo thoracotomy <24 hours were predictors of gastrointestinal complications after coronary artery surgery (all p<0.05). However, stepwise multivariate regression analysis identified CPB inclusive of cardioplegic arrest as the only predictor of post-operative gastrointestinal complications (OR7.4; CI 3.4-17.9). Cardiopulmonary bypass, inclusive of cardioplegic arrest, is the main independent predictor of post-operative gastrointestinal complications in patients undergoing coronary revascularisation.

Is 100% Beating Heart Coronary by-Pass Justified?

Coronary by-pass on a beating heart may provide a safer form of surgical revascularization by avoiding the well-documented side effects of cardiopulmonary by-pass. In addition, off-pump bypass is suggested to be a good alternative to on-pump especially in high risk patients. This study reviews the feasibility of coronary by-pass on the beating heart in all patients referred to surgery. Two hundred and ninety-four patients operated on the beating heart were prospectively followed and compared to the control group of 100 consecutive patients operated with the conventional method. There were no significant differences between the groups with respect to risk factors, except the incidence of chronic obstructive pulmonary disease and ejection fraction which were higher in the conventional group, whereas peripheral vascular disease was higher in the beating heart group. There was more distal anastomosis in the conventional group. Postoperative inotrope requirement, peak creatine phosphokinase—MB, ventilation time, blood loss in the first 24 h, transfusion needs, new atrial fibrillation and length of hospital stay were significantly lower in the beating heart operations. However, there were no significant differences between the groups in terms of neurological complications, chest infection, intraaortic balloon pump usage and mortality. In conclusion, multivessel off pump coronary by-pass is feasible with the same or better results as it is observed in the conventional technique when postoperative bleeding, neurogenic complications, arrythmias. hospital stay, overall morbidity and mortality are compared.

Is 100% beating heart coronary by-pass justified?

Coronary by-pass on a beating heart may provide a safer form of surgical revascularization by avoiding the well-documented side effects of cardiopulmonary by-pass. In addition, off-pump bypass is suggested to be a good alternative to on-pump especially in high risk patients. This study reviews the feasibility of coronary by-pass on the beating heart in all patients referred to surgery. Two hundred and ninety-four patients operated on the beating heart were prospectively followed and compared to the control group of 100 consecutive patients operated with the conventional method. There were no significant differences between the groups with respect to risk factors, except the incidence of chronic obstructive pulmonary disease and ejection fraction which were higher in the conventional group, whereas peripheral vascular disease was higher in the beating heart group. There was more distal anastomosis in the conventional group. Postoperative inotrope requirement, peak creatine phosphokinase- MB, ventilation time, blood loss in the first 24 h, transfusion needs, new atrial fibrillation and length of hospital stay were significantly lower in the beating heart operations. However, there were no significant differences between the groups in terms of neurological complications, chest infection, intraaortic balloon pump usage and mortality. In conclusion, multivessel off pump coronary by-pass is feasible with the same or better results as it is observed in the conventional technique when postoperative bleeding, neurogenic complications, arrythmias, hospital stay, overall morbidity and mortality are compared.