Biomedical subjects
Publications and source records attributed to Nader Moazami.
Reoperations during ventricular assist device (VAD) explantation and subsequent heart transplantation are difficult procedures because of dense adhesions, obliterated planes of dissection, and proximity of the right ventricle to the sternum. We present our approach for left VAD explantation to minimize potential complications that may occur during this procedure.
Both heart failure (HF) and cardiac surgery with cardiopulmonary bypass result in a release of neurohormones, with a variety of physiologic effects. Administration of exogenous B-type natriuretic peptide (BNP) has beneficial hemodynamic effects and reduces the level of several neurohormones in HF patients. BNP is currently being investigated in the perioperative management of cardiac surgery patients and may be especially beneficial for patients with ventricular dysfunction, pulmonary hypertension, or renal dysfunction. Using a neurohormonal approach to supportive therapy may enhance future strategies for patients undergoing cardiac surgery, especially those at greatest risk for complications.
Despite advances in mechanical circulatory support, cardiogenic shock continues to have a high mortality. We reviewed our experience with pulsatile versus non-pulsatile temporary mechanical support at our institution to determine optimal strategy for survival. From January 2001 to December 2003, mechanical support for cardiogenic shock was instituted in 38 patients. Non-pulsatile devices (NP group) were used in 22 patients and pulsatile devices (P group) in 16 patients. Indications for the NP group were post-cardiotomy shock (PCS) in 17, myocardial infarction in 2, and isolated post-cardiotomy right ventricular failure in 3 patients. In the P group, 9 had the device placed for PCS, 3 for viral myocarditis, 1 after myocardial infarction, and 3 for right ventricular (RV) failure. Overall, bleeding, limb ischemia, and multi-system organ failure were higher in NP group with 5 weaned and 3 surviving to discharge (14%). In the P group, survivors included 7 weaned and 3 transplanted patients (63%). With the exception of isolated RV failure, we obtained a dismal survival result with ECMO/centrifugal circuits for treatment of cardiogenic shock. For refractory pump failure, improved survival was achieved by using intermediate-term pulsatile devices with early transition to a chronic device and/or heart transplantation.
BACKGROUND: The purpose of this study was to determine the incidence of neurologic hand complications after radial artery harvesting and to compare the harmonic scalpel versus conventional cold scalpel technique. METHODS: From 1995 to 2000, 786 radial arteries were harvested from 782 patients for coronary artery bypass grafting. From 1995 to 1997, the conventional cold scalpel technique was used (422 patients), and from 1998 to 2000, the harmonic scalpel was used (360 patients). Mean follow-up was 4.2 +/- 2.1 years and was 90% complete. Symptoms included thumb weakness or numbness, tingling, or pain in the hand. RESULTS: The incidence of neurologic hand complications was similar with both techniques (11.2% +/- 3.5% cold, 11.0% +/- 3.6% harmonic, p > 0.95), and in 19% (13 of 67 with symptoms) there was complete resolution within 1 year. Symptoms persisted long-term in 9.0% +/- 3.2% cold scalpel and 9.0% +/- 3.3% harmonic scalpel patients (p > 0.81), but were considered a "constant and significant source of discomfort" in only 0.6% +/- 0.9% cold scalpel and 1.4% +/- 1.3% harmonic scalpel patients (p > 0.41). CONCLUSIONS: The incidence of adverse neurologic outcomes causing significant long-term discomfort in the hand was low using either the cold scalpel or harmonic scalpel technique. However, a significant number of patients had neurologic hand symptoms in both groups, and this should be included when discussing operative risks with the patient.
BACKGROUND: The purpose of this study was to compare operative mortality and midterm outcome of patients with ischemic mitral regurgitation (MR) undergoing either coronary artery bypass grafting (CABG) alone or CABG with mitral valve (MV) repair. METHODS: From 1996 to 2001, 51 consecutive patients underwent CABG with MV repair for ischemic MR. All patients in this group were matched to similar patients with ischemic MR undergoing CABG alone during the same 6-year period using propensity analysis (considering 24 covariates, including severity of MR and New York Heart Association [NYHA] class). RESULTS: Propensity score matching yielded 51 closely matched control patients. Preoperative MR severity was 3+ or 4+ in 94% of CABG with MV repair and 96% of CABG-alone patients, and 86% of patients in each group were NYHA class III or IV. Operative mortality was 3.9% +/- 2.8% in both groups. Survival was also similar between CABG with MV repair and CABG alone at 1 year (84% +/- 5% versus 82% +/- 5%) and 3 years (70% +/- 7% versus 71% +/- 7% (p = 0.43). Among survivors, NYHA class improved at follow-up (50 +/- 20 months) from 3.4 +/- 0.7 to 1.7 +/- 1.0 for CABG with MV repair (p < 0.001) and from 3.4 +/- 0.7 to 1.8 +/- 1.0 for CABG alone (p < 0.001). CONCLUSIONS: Operative mortality, midterm survival, and late functional class were similar between two well-matched groups of patients undergoing CABG for ischemic MR, differing only in the addition of MV repair. Whereas MV repair can be added safely to CABG in this group of high-risk patients without increasing mortality, its impact on late survival and functional class may be limited.
BACKGROUND: Patients with acute right ventricular (RV) failure after cardiotomy have a poor prognosis. We evaluated the surgical and long-term outcomes of patients with isolated RV failure that required right ventricular assist device (RVAD) support. METHODS: Between 1991 and 2002, a total of 30 patients received RVAD support for isolated RV dysfunction. We evaluated survival, duration of mechanical support, post-RVAD hemodynamics, and RV function. RESULTS: Right ventricular failure developed in patients after coronary artery bypass surgery alone or combined with valve surgery (12 patients), valvular surgery (5), ascending aortic replacement (6), heart transplantation (3), and pulmonary endarterectomy (4). Mean age was 58 +/- 15 years, and 17 (57%) were women. Surgery was emergent in 5 (73%) patients. Centrifugal pumps were used in 21, extra corporeal membrane oxygenation in 8, and as Abiomed pump in 1 patient. Overall, 17 (57%) patients died while receiving assist device support, 3 of sepsis, 2 of stroke, and 12 of inability to wean from the device. We successfully weaned RVAD support in 13 (43%) patients, with a median duration of support of 5 days (range, 2-8 days). Ten survived to hospital discharge. After RVAD removal, mean pulmonary artery pressure was 25.1 +/- 6.5 mmHg, cardiac output was 4.8 +/- 2.0 liters, and central venous pressure was 16.5 +/- 3.7 mmHg. Echocardiogram after RVAD removal showed normal RV function in 2 patients and in 11 patients demonstrated improvement. CONCLUSION: After cardiotomy, patients with RV failure who require mechanical support continue to have increased mortality. For patients successfully weaned from the RVAD, residual RV dysfunction is compatible with survival. More liberal use of RV mechanical support may be indicated for patients with acute RV failure.
BACKGROUND: The purpose of this study was to describe our institutional experience in using inhaled prostacyclin as a selective pulmonary vasodilator in patients with pulmonary hypertension, refractory hypoxemia, and right heart dysfunction after cardiothoracic surgery. METHODS: Between February 2001 and March 2003, cardiothoracic surgical patients with pulmonary hypertension (mean pulmonary artery pressure >30 mm Hg or systolic pulmonary artery pressure >40 mm Hg), hypoxemia (PaO(2)/fraction of inspired oxygen <150 mm Hg), or right heart dysfunction (central venous pressure >16 mm Hg and cardiac index <2.2 L.min(-1).m(-2)) were prospectively administered inhaled prostacyclin at an initial concentration of 20,000 ng/mL and then weaned per protocol. Hemodynamic variables were measured before the initiation of inhaled prostacyclin, 30 to 60 minutes after initiation, and again 4 to 6 hours later. RESULTS: One hundred twenty-six patients were enrolled during the study period. At both time points, inhaled prostacyclin significantly decreased the mean pulmonary artery pressure without altering the mean arterial pressure. The average length of time on inhaled prostacyclin was 45.6 hours. There were no adverse events attributable to inhaled prostacyclin. The average cost for inhaled prostacyclin was 150 US dollars per day. Compared with nitric oxide, which costs 3000 US dollars per day, the potential cost savings over this period were 681,686 US dollars. CONCLUSIONS: Inhaled prostacyclin seems to be a safe and effective pulmonary vasodilator for cardiothoracic surgical patients with pulmonary hypertension, refractory hypoxemia, or right heart dysfunction. Overall, inhaled prostacyclin significantly decreases mean pulmonary artery pressures without altering the mean arterial pressure. Compared with nitric oxide, there is no special equipment required for administration or toxicity monitoring, and the cost savings are substantial.
OBJECTIVE: End-stage heart failure has been associated with high mortality in the absence of transplantation. We evaluated the outcome of patients receiving optimal medical therapy who were removed from the cardiac transplant waiting list to determine survival and predictors of mortality. METHODS: We performed a retrospective review of 27 patients removed from the cardiac transplant waiting list from 1999 to 2001 at our institution. RESULTS: Mean age was 53 +/- 11 years; 16 of the patients were male. Status was IB in 3 cases and II in 24. Median time on the list was 32 months, and median follow-up was 2.9 years. Patients were removed from the transplant list because of either clinical improvement (group A, n = 18) or deterioration (group B, n = 9). In group A, 13 patients had improved functional status and 10 were in New York Heart Association class 1 or 2; 16 had improved echocardiographic left ventricular function. Survivals at 3 years were 100% in group A and 44% in group B (P <.01). CONCLUSION: Patients with end-stage heart failure who have clinical response to medical therapy have excellent 3-year survival. These data suggest the necessity of close evaluation of patients waiting for transplantation, with a low threshold for inactivation if persistent clinical improvement is observed.
A unique case of spontaneous multivessel coronary artery dissection in a young woman without identifiable risk factors, who remained asymptomatic despite extensive coronary dissection is presented. The management of this condition and a review of the current literature on this subject are presented.
Recombinant human B-type natriuretic peptide (BNP) is a promising new agent in the management of heart failure. The pharmacologic properties of BNP make it desirable to use in a subset of patients after cardiac surgical operations. Among these therapeutic potentials is the effect on markedly reducing pulmonary vascular resistance and central venous pressure with mild systemic vasodilatation. In addition, BNP directly effects the kidneys to promote natriuresis. We believe this agent to be useful in the treatment of the postcardiac surgery patients with left ventricular dysfunction and mild to moderate renal insufficiency. This report summarizes our experience in 2 patients.
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OBJECTIVES: This study was undertaken to identify management strategies that maximize survival of patients with stage III non-small cell lung cancer and metachronous brain metastases and to determine whether any apparent improved survival was due to treatment or simply to patient selection. METHODS: Treatment evaluations of both primary non-small cell lung cancer and brain metastases were performed in 91 patients. Optimal treatment was identified by multivariable analysis. Propensity scoring and multivariable analysis were used to separate treatment benefit from patient selection. RESULTS: Risk-unadjusted median, 12-, and 24-month survivals were 5.2 months, 22%, and 10%, respectively. Younger age (P =.006), good performance status (P =.003), stage IIIA (P =.001), lung resection (P =.02), no other systemic metastases at time of diagnosis of brain metastases (P =.02), and either metastasectomy (P <.001) or stereotactic radiosurgery (P <.001) predicted best survival. However, metastasectomy or stereotactic radiosurgery was more common after lung resection (P =.02) and in patients with good performance status (P =.006), no other systemic metastases at time of diagnosis of brain metastases (P =.01), and fewer brain metastases (P <.001), suggesting that the patients with the best risk profile were selected for aggressive therapy of both lung primary and brain metastases. Despite this selection, analysis of propensity-matched patients demonstrated the benefit of lung resection and metastasectomy or stereotactic radiosurgery (P <.001). CONCLUSIONS: Younger patients with resected stage IIIA non-small cell lung cancer who have isolated metachronous brain metastases and good performance status do best when treated with metastasectomy or stereotactic radiosurgery. This survival benefit is a brain treatment effect, not the result of selecting the best patients for aggressive therapy.
BACKGROUND: The surgical treatment of mitral valve regurgitation (MR) at the time of aortic valve replacement (AVR) remains controversial. The purpose of this study was to evaluate the change in severity of MR following isolated AVR, and to determine survival benefit. METHODS: Between 1991 and 2001, 250 patients underwent isolated AVR; 196 patients had concomitant functional MR. Follow-up transthoracic echocardiography (TTE) was available on 107 patients, with a median of 818 +/- 752 days. Aortic valve was stenotic in 77 and regurgitant in 30 patients. RESULTS: Mean age was 67 +/- 15 years and 57 (53%) were male. Preoperative MR was trivial (1+) in 27 (25%), mild (2+) in 44 (41%), moderate (3+) in 29 (27%), and severe (4+) in 7 (7%). At follow-up TTE, MR improved by 1 or 2 grades in 48 patients (45%). Of patients with preoperative 2+ MR, 19 (43%) improved, 16 (36%) remained unchanged, and 9 (21%) worsened. Although some patients with preoperative 3+ MR exhibited improvement, 11 (38%) remained with moderate-to-severe MR. Of those with a preoperative MR of 4+, 3 (71%) improved, and 4 remained with 3-4+ MR. For patients with preoperative 1 to 2+ MR, survival at 3 years was 98% compared to 78% for those with 3 to 4+ MR (p = 0.038). CONCLUSION: Functional MR does not always improve after isolated AVR. Survival is lower for patients with preoperative 3 to 4+ MR. Moderate-to-severe MR should be repaired at the time of aortic valve surgery.
BACKGROUND: With improved survival following renal transplantation, the number of patients undergoing cardiac surgery has increased. The purpose of this study was to review the morbidity, mortality, and allograft function in renal transplant patients undergoing major cardiac surgery. METHODS: Retrospective database review of consecutive renal transplant patients undergoing cardiac surgery from 1987 to 2002. Patients requiring dialysis (D) before cardiac surgery versus those with stable renal transplants (ND) were compared. RESULTS: Cardiac surgery was performed in 46 patients during the study period. Twenty patients (42%) required dialysis (D) before surgery while 26 (58%) had stable allograft function (ND). Among patients who had stable allograft function prior to surgery, there was no allograft loss. In the ND group, preoperative and discharge creatinine levels were 2.17 +/- 1.0 and 2.4 +/- 1.5 mg/dL, respectively. All operative deaths occurred in the dialysis dependent group. The 30-day and 3-year survival, respectively was 80% and 20% in the D group compared to 100% and 69% amongst the ND group (p </= 0.01). Infectious complications consisted of pneumonia and sepsis each in 8.5% and of deep sternal wound infection in 4.3% of the entire group. CONCLUSIONS: (1) Morbidity and mortality of cardiac surgery in renal transplant patients with stable allograft function is low and stable allograft function can be maintained without allograft loss. (2) Mortality following cardiac surgery is significantly higher among renal transplant patients who become dialysis dependent and intermediate-term survival is poor.