Have changes in ECMO technology impacted outcomes in adult patients developing postcardiotomy cardiogenic shock?

Extracorporeal membrane oxygenation (ECMO) technology has undergone several advancements over the last decade. We sought to compare current ECMO technology to older ones to determine how these technological improvements have impacted outcomes in patients suffering from postcardiotomy cardiogenic shock (PCS). Between 2005 and 2010, 49 patients received ECMO as support for PCS following elective cardiac surgery. Patients were divided into three groups. Group 1 (Gp 1, n = 11) patients received a Biomedicus pump with an Affinity oxygenator, Group 2 (Gp 2, n = 11) patients received a Biomedicus pump with a Quadrox D oxygenator, and Group 3 (Gp 3, n = 27) patients received a Rotaflow pump with a Quadrox D oxygenator. Groups were compared with regards to adverse events and ability to wean. Adverse event analysis showed no statistically significant difference between groups in incidence of stroke (p = 0.08), renal failure (p = 0.88), or bleeding requiring reexploration (p = 0.10). Changes in technology did little to improve weaning rates from ECMO (Gp 1 = 63.6%, Gp 2 = 45.5%, and Gp 3 = 55.6%). Similar trends were detected in hospital survival (Gp 1 = 27.3%, Gp 2 = 27.3%, and Gp 3 = 33.3%). Technology did impact oxygenator durability with Gp 1 requiring seven (63.6%) oxygenator exchanges compared to zero (0.0%) in Gp 2 and two (7.4%) in Gp 1. While advancements in ECMO technology have resulted in improved oxygenator durability, outcomes in patients requiring such support for PCS continue to be poor.

Regional referral system for patients with acute mechanical support: experience at the Cleveland Clinic Foundation.

Regional referral networks ("hub and spoke") have been created to facilitate the transfer of patients on mechanical circulatory support. Although individual centers report good success, overall outcomes have remained poor. We investigated whether preoperative variables influenced survival and could be used to help select patients best served by referral. A retrospective chart review was conducted on all patients transferred to our institution supported on cardiac assist devices. Between January 1995 and September 2003, 39 patients were received in transfer for continued care after the implantation of a cardiac assist device. Eighty-five percent of patients had the ABIOMED BVS 5000 implanted. The most common indication was postcardiotomy shock. Sixty-four percent of patients were not candidates for heart transplantation due to medical or social contraindications. The 30-day mortality of this group was 62%. Survivors had less comorbidity and were less likely to have complex surgeries, neurologic impairment, and multisystem organ failure when presenting to our center. Devices were weaned in 30% of cases. Only six patients (15%) were successfully transplanted, and five of these patients have done well at follow-up. Based on our experience, we believe that cardiogenic shock patients benefit from a regional referral system if they have not had complex cardiac surgical procedures or developed multisystem organ failure. Furthermore, there is a survival advantage when using long-term devices because this allows possible recovery or transplantation.

Predictors of severe right ventricular failure after implantable left ventricular assist device insertion: analysis of 245 patients.

BACKGROUND: Insertion of an implantable left ventricular assist device (LVAD) complicated by early right ventricular (RV) failure has a poor prognosis and is largely unpredictable. Prediction of RV failure after LVAD placement would lead to more precise patient selection and optimal device selection. METHODS AND RESULTS: We reviewed data from 245 patients (mean age, 54+/-11 years; 85% male) with 189 HeartMate (77%) and 56 Novacor (23%) LVADs. Ischemic cardiomyopathy predominated (65%), and 29% had dilated cardiomyopathy. Overall, RV assist device (RVAD) support was required after LVAD insertion for 23 patients (9%). We compared clinical and hemodynamic parameters before LVAD insertion between RVAD (n=23) and No-RVAD patients (n=222) to determine preoperative risk factors for severe RV failure. By univariate analysis, female gender, small body surface area, nonischemic etiology, preoperative mechanical ventilation, circulatory support before LVAD insertion, low mean and diastolic pulmonary artery pressures (PAPs), low RV stroke work (RVSW), and low RVSW index (RVSWI) were significantly associated with RVAD use. Elevated PAP and pulmonary vascular resistance were not risk factors. Risk factors by multivariable logistic regression were preoperative circulatory support (odds ratio [OR], 5.3), female gender (OR, 4.5), and nonischemic etiology (OR, 3.3). CONCLUSIONS: The need for circulatory support, female gender, and nonischemic etiology were the most significant predictors for RVAD use after LVAD insertion. Regarding hemodynamics, low PAP and low RVSWI, reflecting low RV contractility, were important parameters. This information may lead to better patient selection for isolated LVAD implantation.

Severe renal dysfunction complicating cardiogenic shock is not a contraindication to mechanical support as a bridge to cardiac transplantation.

OBJECTIVES: This study investigated outcomes in patients with cardiogenic shock and severe renal dysfunction treated with ventricular assist devices (VAD) as a bridge to cardiac transplantation. BACKGROUND: Previous reports have documented poor survival in patients with cardiogenic shock and severe renal dysfunction treated with VAD. METHODS: We surveyed 215 consecutive patients who received a VAD from 1992 to 2000 and selected patients who had a serum creatinine > or =3.0 mg/dl at the time of VAD placement. Demographic, laboratory, and clinical outcome data were collected. RESULTS: Eighteen patients met the inclusion criteria. Mean serum creatinine at the time of VAD placement was 4.0 +/- 0.7 mg/dl (range 3.0 to 5.2 mg/dl). Seven patients required temporary renal support with continuous venovenous hemodialysis (CVVHD). Eleven patients underwent cardiac transplantation. At six months post-transplantation, mean serum creatinine was 2.0 +/- 0.6 mg/dl (range 1.3 to 3.5 mg/dl). None of the transplanted patients required subsequent renal support. Seven patients died with a VAD before transplantation. Three died early (<1 month) after VAD placement, and all three required CVVHD until death. Four patients survived for >1 month after VAD placement; all four had resolution of renal dysfunction with mean serum creatinine of 1.9 +/- 1.2 mg/dl (range 0.8 to 3.6 mg/dl) without the need for renal support. Overall 30-day and six-month survival after VAD placement, survival to transplantation, and survival one year post-transplantation were similar to patients without severe renal dysfunction. CONCLUSIONS: Contemporary use of VAD leads to resolution of severe renal dysfunction in most cardiogenic shock patients and comparable long-term outcomes to patients without renal dysfunction.

Noninvasive assessment of cardiac mechanics and clinical outcome after partial left ventriculectomy.

BACKGROUND: Partial left ventriculectomy (PLV) was developed as a therapy for end-stage heart failure, but results were variable with few a priori predictors of outcome. Little is known about its effects on myocardial mechanics and their relation to clinical outcome. METHODS: Twenty-four dilated cardiomyopathy patients underwent cardiac magnetic resonance imaging (MRI) before PLV, and 3 and 12 months after surgery. Left ventricular (LV) circumferential shortening and wall stress were computed at three short-axis levels. Exploratory outcome analysis grouped patients according to the timing of adverse cardiac events postsurgery. RESULTS: LV mass and volume were decreased at each postsurgical time point (all p < 0.01). At 3 months, regional wall stress was reduced at all short-axis levels; but by 12 months stress was reduced from baseline only at the apex. Circumferential shortening was increased significantly at both postsurgical time points at each level. On average, septal shortening was negative (stretching) before surgery, but increased significantly, and was positive, postsurgery. Exploratory outcome analysis found that negative values of basal septum circumferential shortening before surgery increased the probability of event-free survival beyond 6 months. CONCLUSIONS: Regional heterogeneity of LV myocardial function, associated with dilated cardiomyopathy, was diminished after PLV but was also related to patient outcome. MRI with tissue tagging is useful for assessing the efficacy of surgical therapies for congestive heart failure.

The impact of hypogammaglobulinemia on infection outcome in patients undergoing ventricular assist device implantation.

BACKGROUND: Infection is a major comorbidity after ventricular assist device (VAD) placement. Defects in cellular immunity have been reported after VAD placement. However, to our knowledge, quantitative immunoglobulin G (IgG) level determination and the impact of hypogammaglobulinemia (HGG) on infections after VAD implantation have not been evaluated before. METHODS: A total of 76 patients (mean age, 53 years) underwent VAD implantation as a bridge to transplantation and had IgG levels determined as a baseline before transplantation. Patients were divided into 2 groups according to IgG level: Control Group (n = 56, IgG > or = 700 mg/dl) and HGG Group (n = 20, IgG < 700 mg/dl). Infection outcome during the VAD course and after transplantation was analyzed in relation to the IgG level. RESULTS: Baseline characteristics were similar in both groups. The incidence of bacteremia (14/20 [70%] vs 18/56 [32%], p = 0.0032) and major infection (19/20 [95%] vs 31/56 [56%], p = 0.0009) were significantly increased in the HGG Group compared with the Control Group. After transplantation, the episodes of rejection were similar in both groups and survival was similar. The HGG Group experienced more cytomegalovirus infections compared with the Control Group (9/20 [45%] vs 9/56 [16%], p = 0.009). CONCLUSIONS: VAD patients with HGG are at increased risk of infections. After transplantation, these patients also experience increased cytomegalovirus infections. A randomized preemptive IgG replacement trial may be warranted in the future to determine if this intervention will alleviate the risk of infection.

The impact of CytoGam on cardiac transplant recipients with moderate hypogammaglobulinemia: a randomized single-center study.

BACKGROUND: We have previously shown that the preemptive use of cytomegalovirus (CMV) immunoglobulin (Ig) replacement (CytoGam) decreases the incidence of opportunistic infections in cardiac transplant recipients with severe hypogammaglobulinemia. However, the impact of Ig replacement in moderately hypogammaglobulinemic patients is unknown. METHODS: Periodic monitoring of the IgG levels was done in 300 heart transplant recipients. Moderate hypogammaglobulinemia (IgG, 350-500 mg/dl) developed in 56 patients (18.6%). Thirty-three patients declined randomization but agreed to have their IgG levels monitored. Twenty-three patients were randomized to placebo (n = 10) or CytoGam (n = 13) at 105 +/- 63 days after transplantation. RESULTS: The baseline characteristics were similar. A significant reduction in CMV infection was noted in the CytoGam Group compared with the Placebo Group (15.4% [2/13] vs 60% [6/10], p = .039). Among patients who declined randomization, CMV infection developed in 13 (39.4%) of 33, and 6 (46.1%) of the 13 progressed to severe hypogammaglobulinemia. A trend for reduction in the average episodes of > or =grade 2 rejection during the 6-month period after randomization was noted in the CytoGam group (0.4 +/- 0.6 vs 1.4 +/- 1.3, p = 0.065). CONCLUSIONS: The preemptive use of CytoGam decreases the incidence of CMV infection in patients with moderate hypogammaglobulinemia. A larger randomized study is needed to substantiate these results.

PET abnormalities in patients with nonischemic cardiomyopathy.

BACKGROUND: The abnormalities in dilated cardiomyopathy (DCM) are generally considered diffuse and to affect the left ventricle in a global manner. However, regional wall motion abnormalities and metabolic defects may also occur to varying, but unclear degrees. QRS width and metabolic defects on positron emission tomography (PET) correlate with survival. We sought to ascertain the prevalence of regional defects in DCM by multiple imaging modalities and to establish the relationship between QRS width and these defects. METHODS: In consecutive patients with advanced nonischemic DCM, undergoing cardiac transplant evaluation, we reviewed multiple imaging modalities (PET, 2-dimensional echocardiography, and radionuclide ventriculography) to quantify the incidence of regional metabolic and wall motion abnormalities and correlate them with clinical and electrocardiographic parameters. RESULTS: Of 44 patients studied, PET imaging revealed scar in 91% of patients, with a mean of 25 +/- 18% of the left ventricle involved, predominantly in the distribution of the left anterior descending artery. Regional wall motion abnormalities occurred in 51% of patients who underwent echocardiography and 59% of patients who underwent nuclear scintigraphy (with only 70% concordance). QRS duration on the surface electrocardiogram correlated positively with the degree of scarring (r=.52, P=.0007). CONCLUSIONS: The presence of scar (matched perfusion and metabolic defects) on PET scanning in patients with advanced DCM is not always indicative of coronary disease. Thus coronary angiography is usually required to define the etiology of systolic dysfunction. The extent of scar correlates with QRS duration. This may have implications for the application of cardiac resynchronization therapy.