Adult congenital heart disease: frequency, risk factors and outcomes of acute kidney injury in postoperative period

Effect of a Machine Learning-Derived Early Warning Tool With Treatment Protocol on Hypotension During Cardiac Surgery and ICU Stay: The Hypotension Prediction 2 (HYPE-2) Randomized Clinical Trial

OBJECTIVES

Cardiac surgery is associated with perioperative complications, some of which might be attributable to hypotension. The Hypotension Prediction Index (HPI), a machine-learning-derived early warning tool for hypotension, has only been evaluated in noncardiac surgery. We investigated whether using HPI with diagnostic guidance reduced hypotension during cardiac surgery and in the ICU.

DESIGN

Randomized clinical trial conducted between May 2021 and February 2023.

SETTING

Single-center study conducted in an academic hospital in the Netherlands.

PATIENTS

Adults undergoing elective on-pump coronary artery bypass grafting, with or without single heart valve surgery, were enrolled if a mean arterial pressure (MAP) greater than or equal to 65 mm Hg was targeted during the surgical off-pump phases and ICU stay. After eligibility assessment, 142 of 162 patients approached gave informed consent for participation.

INTERVENTIONS

Patients randomized 1:1 received either diagnostic guidance in addition to standard care if HPI reached greater than or equal to 75 ( n = 72) or standard care alone ( n = 70).

MEASUREMENTS AND MAIN RESULTS

The primary outcome was the severity of hypotension, measured as time-weighted average (TWA) of MAP less than 65 mm Hg. Secondary outcomes encompassed hypertension severity and intervention disparities. Of 142 patients randomized, 130 were included in the primary analysis. The HPI group showed 63% reduction in median TWA of hypotension compared with the standard care group, with a median of differences of -0.40 mm Hg (95% CI, -0.65 to -0.27; p < 0.001). In the HPI group, patients spent a median 28 minutes (95% CI, 17-44 min) less in hypotension, with a measurement duration of 322 minutes in the HPI group and 333 minutes in the standard care group. No significant differences were observed in hypertension severity, treatment choice, or fluid, vasopressors, and inotrope amounts.

CONCLUSIONS

Using HPI combined with diagnostic guidance on top of standard care significantly decreased hypotension severity in elective cardiac surgery patients compared with standard care.

Assessing Risk Factors for Prolonged Intensive Care Unit Stay After Surgery for Adult Congenital Heart Disease: A Study From a Lower-Middle-Income Country

Background Prolonged post-surgery intensive care unit (ICU) stay for congenital heart disease (CHD) has been explored in the pediatric population. However, there is limited data for adult CHD (ACHD), also called grown-up congenital heart (GUCH) disease, especially in low-resource countries where intensive care beds are scarce. This study identifies factors associated with prolonged ICU stay following surgery for ACHD in Pakistan, a lower-middle-income country (LMIC). Methods This retrospective study included all adult patients (⩾18 years) who underwent cardiac surgery with cardiopulmonary bypass for their CHD from 2011-2016 at a tertiary-care private hospital in Pakistan. Prolonged ICU stay was defined as stay >6 days (75^th percentile). Regression analysis was used to explore risk factors of prolonged ICU stay. Results A total of 166 patients (53.6% males) with a mean age of 32.05 ± 12.11 years were included. Atrial septal defect repair was the most common surgery (42.2%). Most patients were categorized as Risk Adjustment for Congenital Heart Surgery 1 (RACHS-1) Category 1 (51.8%) and Category 2 (30.1%). Forty-three of 166 patients (25.9%) experienced prolonged ICU stay. Complications occurred in 38.6% of patients postoperatively, with the most common being acute kidney injury (29.5%). On multivariable logistic regression adjusted for age, gender, and RACHS-1 categories, intraoperative inotrope score, cardiopulmonary bypass time, aortic cross-clamp time duration of mechanical ventilation, and postoperative acute kidney injury (AKI) were associated with prolonged ICU stay. Conclusion Surgeons managing ACHD in LMICs must strive for shorter operative durations and the judicious use of intraoperative inotropes in addition to anticipating and promptly managing postoperative complications such as AKI, to minimize ICU stay in countries where intensive care beds are a scarce resource.

Risk factors and outcomes of prolonged cardiopulmonary bypass time in surgery for adult congenital heart disease: a single-center study from a low-middle-income country

BACKGROUND

Prolonged cardiopulmonary bypass time (prolonged CPBT; PCPBT) during operations for adult congenital heart disease (ACHD) may lead to worse postoperative outcomes, which could add a significant burden to hospitals in developing countries. This study aimed to identify risk factors and outcomes of PCPBT in patients undergoing operations for ACHD.

METHODS

This retrospective study included all adult patients (≥18 years) who underwent cardiac surgery with cardiopulmonary bypass for their congenital heart defect from 2011-2016 at a tertiary-care private hospital in Pakistan. Prolonged CPBT was defined as CPBT>120 minutes (65^th percentile).

RESULTS

This study included 166 patients (53.6% males) with a mean age of 32.05±12.11 years. Comorbid disease was present in 59.0% of patients. Most patients underwent atrial septal defect repair (42.2%). A total of 58 (34.9%) of patients had a PCPBT. Postoperative complications occurred in 38.6% of patients. Multivariable analysis adjusted for age, gender and RACHS-1 Categories showed that mild preoperative left ventricular (LV) dysfunction was associated with PCPBT (OR=3.137 [95% CI: 1.003-9.818]), while obesity was found to be protective (0.346 [0.130-0.923]). PCPBT was also associated with a longer duration of ventilation (1.298 [1.005-1.676]), longer cardiac ICU stay (1.204 [1.061-1.367]) and longer hospital stay (1.120 [1.005-1.247]).

CONCLUSIONS

While mild preoperative LV dysfunction was associated with PCPBT, obesity was found to be protective. Postoperatively, PCPBT was associated with longer duration of ventilation, cardiac ICU stay, and hospital stay. Operations with shorter CPBT may help minimize the occurrence and impact of these postoperative adverse outcomes especially in resource-constrained developing countries.

Incidence, Predictors, and Impact of Postoperative Acute Kidney Injury Following Fontan Conversion Surgery in Young Adult Fontan Survivors

Acute kidney injury (AKI) is a common complication following single ventricle congenital heart surgery. Data regarding AKI following Fontan conversion (FC) surgery are limited. This study evaluated the incidence, predictors of, and prognostic value of AKI following FC. Single-center retrospective cohort study, including consecutive FC patients from December 1994 to December 2016. Medical records were reviewed. AKI was classified into AKI-1/AKI-2/AKI-3 using Kidney Disease: Improving Global Outcomes criteria. Multivariable logistic regression identified risk factors for AKI≥2. Chi-square and 2-sample t-tests assessed associations between AKI≥2 and postoperative outcomes. Mid-term heart-transplant-free survival among AKI0-1 vs AKI2-3 groups was compared using Kaplan-Meier curves and log-rank test. We included 139 FC patients: age at FC 24 (25th-75th, 19-31) years; 81% initial atrio-pulmonary Fontan; follow-up 8.3 ± 5.3 years following FC. Post-FC, 63 patients (45%) developed AKI (AKI-1 = 37 [27%]; AKI-2 = 10 [7%]; AKI-3 = 16 [11%]). AKI recovered by hospital discharge in 86%, 80%, and 19% of patients with AKI-1/AKI-2/AKI-3, respectively. Independent risk factors for AKI≥2 included older age (OR 1.07, 95%CI 1.01-1.15; P = 0.027); ≥3 prior sternotomies (OR = 6.11; 95%CI = 1.59-23.47; P = 0.009); greater preoperative right atrial pressure (OR 1.19; 1.02-1.38; P = 0.024), and prior catheter ablation procedure (OR 3.45; 1.17-10.18; P = 0.036). AKI≥2 was associated with: longer chest tube duration (9 [5-57] vs 7 [3-28] days; P = 0.01); longer mechanical ventilation time (2 [1-117] vs 1 [1-6] days; P = 0.01); greater need for dialysis (31% v s0%; P < 0.001); and longer postoperative length of stay (18 [8-135] vs 10 [6-58] days; P < 0.001). AKI 2-3 patients had worse mid-term heart-transplant-free survival. Half of the patients undergoing FC develop AKI. AKI 2-3 is associated with worse early postoperative outcomes and reduced mid-term transplant-free survival following FC. Knowledge of AKI predictors may allow for improved FC risk stratification, patient selection, and perioperative management in this high-risk population.

Prolonged length of stay after surgery for adult congenital heart disease: a single-centre study in a developing country

BACKGROUND

With the growing number of adults requiring operations for CHD, prolonged length of stay adds an additional burden on healthcare systems, especially in developing countries. This study aimed to identify factors associated with prolonged length of stay in adult patients undergoing operations for CHD.

METHODS

This retrospective study included all adult patients (≥18 years) who underwent cardiac surgery with cardiopulmonary bypass for their CHD from 2011 to 2016 at a tertiary-care private hospital in Pakistan. Prolonged length of stay was defined as hospital stay >75th percentile of the overall cohort (>8 days).

RESULTS

This study included 166 patients (53.6% males) with a mean age of 32.05 ± 12.11 years. Comorbid disease was present in 59.0% of patients. Most patients underwent atrial septal defect repair (42.2%). A total of 38 (22.9%) patients had a prolonged length of stay. Post-operative complications occurred in 38.6% of patients. Multivariable analysis showed that pre-operative body mass index (odds ratio: 0.779; 95% confidence interval: 0.620-0.980), intraoperative aortic cross-clamp time (odds ratio: 1.035; 95% confidence interval: 1.009-1.062), and post-operative acute kidney injury (odds ratio: 7.392; 95% confidence interval: 1.036-52.755) were associated with prolonged length of stay.

CONCLUSION

Predictors of prolonged length of stay include lower body mass index, longer aortic cross-clamp time, and development of post-operative acute kidney injury. Shorter operations, improved pre-operative nutritional optimisation, and timely management of post-operative complications could help prevent prolonged length of stay in patients undergoing operations for adult CHD.