Pathological assessment of end-stage heart failure in explanted hearts in correlation with hemodynamics in patients undergoing orthotopic heart transplantation.

BACKGROUND: To date, there has been little research, if any, on the pathological correlates of end-stage heart failure in the explanted hearts of orthotopic heart transplant (OHT) recipients in correlation with the patients' hemodynamics. We sought to compare the gross and histopathological parameters in hearts explanted-native or previously transplanted-from patients with end-stage heart failure with the clinical hemodynamics parameters at the time of OHT. METHODS: Forty patients undergoing OHT were enrolled in this study and divided into two groups according to whether they suffered from ischemic (ICMP) or nonischemic cardiomyopathy (NICMP). All study patients were treated with OHT for end-stage heart failure at The University of Texas Health Science Center at Houston. The pathological investigations of the hearts were focused on the study of the underlying cause of heart failure leading the patient to OHT; on the quantification of the extent and severity of fibrosis, hypertrophy, and myocytolysis; and on validating a semiquantitative grading scale. Analyses of multiple sections of the explanted hearts were carried out. The heart weights were recorded and compared with the grades of fibrosis, hypertrophy of cardiomyocytes, and myocytolysis. The grades of fibrosis, hypertrophy, and myocytolysis were evaluated in right and left ventricles and atria (with areas of confluent infarction excluded). The pathological parameters were correlated with the patients' clinical parameters. RESULTS: Twenty-two patients (20 men, 2 women, mean age±S.E.M., 62.3±2.2 years) suffered from ICMP and 18 patients (9 men, 9 women, mean age±S.E.M., 56.3±2.8 years) from NICMP. All the clinical and pathological measured variables were comparable between the two groups, except for pulmonary vascular resistance, which was higher in the NICMP group of patients, and the grade of myocytolysis, which was significantly higher in the ICMP vs. NICMP group. Most of the clinical and pathological variables were overall linearly correlated. CONCLUSIONS: Both ICMP and NICMP groups of end-stage heart failure requiring OHT presented high grades of fibrosis, hypertrophy, and myocytolysis. Heart failure is the final common pathway of a variety of primary cardiovascular diseases regardless of the ischemic or nonischemic nature of the cardiomyopathy.

Establishment of a transcatheter aortic valve program and heart valve team at a Veterans Affairs facility.

BACKGROUND: The US Food and Drug Administration recently approved a transcatheter aortic valve for patients for whom open heart surgery is prohibitively risky. METHODS: A multidisciplinary heart valve team partnered with administration to launch a transcatheter aortic valve replacement (TAVR) program. Clinical registries were used to show robust valve caseloads and outcomes at our Veterans Affairs (VA) facility and to project future volumes. A TAVR business plan was approved by the VA leadership as part of a multiphase project to upgrade and expand our surgical facilities. RESULTS: The heart valve team completed a training program that included simulations and visits to established TAVR centers. Patients were evaluated and screened through a streamlined process, and the program was initiated successfully. CONCLUSIONS: Establishing a TAVR program at a VA facility requires a multidisciplinary team with experience in heart valve and endovascular therapies and a supportive administration willing to invest in a sophisticated infrastructure.

Extracorporeal membrane oxygenation using the TandemHeart System's catheters.

We describe the initial--and successful--use of the TandemHeart System's catheters to provide extracorporeal membrane oxygenation (ECMO), in 2 patients. In 1 patient, who was experiencing severe primary respiratory failure, the catheters provided a standard venovenous ECMO circuit. In the other patient, who had severe, acute pulmonary hypertension and right-heart failure, the catheters enabled a novel right atrial-to-left atrial circuit for ECMO. We discuss the potential of the TandemHeart System's catheters to provide novel and possibly superior vascular routes for the delivery of ECMO in different types of cardiopulmonary failure.

Assessment of arterial blood pressure during support with an axial flow left ventricular assist device.

BACKGROUND: Axial-flow left ventricular assist devices (LVADs) have a number of advantages over pulsatile LVADs, including their small size and better durability. Although the design of axial-flow pumps should result in fewer serious complications during support, some adverse events persist. Thus, optimizing patient treatment may minimize complications, allowing broader acceptance of these devices. In this study, we analyzed standard blood pressure measurements obtained by cuff and arterial lines and used these values to help establish guidelines for the safe operation of axial-flow LVADs. METHODS: The study included 35 heart failure patients who had received a Jarvik 2000 (Jarvik Heart Inc, New York, NY) axial-flow LVAD as a bridge to cardiac transplantation. Blood pressure and echocardiographic data were collected during speed-change studies. RESULTS: Systolic blood pressure did not change, but diastolic, mean, and pulse pressure values changed significantly with changes in pump speed (p < 0.0001). When blood pressure values obtained from an arterial line were compared with those from an automated cuff machine, the systolic, diastolic, and mean values did not correlate (p < 0.05), but the calculated pulse pressures did (p = 0.33). A pulse pressure calculation of < 15 mm Hg resulted in aortic valve opening 24% of the time, and a pulse pressure > 15 mm Hg was predictive of aortic valve opening 65% of the time. CONCLUSIONS: Because aortic valve opening minimizes the risk of complications, a safe zone for most patients is a pulse pressure > 15 mm Hg. Arterial blood pressure changes during axial-flow LVAD support can be predicted and may be used as a guide for the proper management of pump speed settings. A calculated pulse pressure from an arterial line or automated cuff may be used to determine a safe zone of Jarvik 2000 operation, leading to fewer complications.