Obstacles to early discharge after cardiac surgery.

CONTEXT: Cardiovascular disease and cardiac surgery, in particular, are associated with a large expenditure of healthcare resources. Identifying the factors that affect length of stay for patients hospitalized for cardiac surgery and ways to safely and effectively shorten stays could have significant impact on healthcare costs. OBJECTIVE: To identify obstacles to and the effects of early discharge on outcome after cardiac surgery. STUDY DESIGN: A prospective approach using a protocol consisting of modifying anesthesia, limiting the use of postoperative narcotics, early extubation, and early mobilization, with a goal of discharge at < 5 days. PATIENTS AND METHODS: The study group consisted of 422 consecutive patients (age range 15-89 years, 65% males): coronary artery bypass graft (CABG) (n = 290), valve procedures (n = 54), and CABG + valve procedures (n = 78). The discharge criteria included hemodynamic stability, normal bowel function, independence in activities of daily living, absence of fever, and no incision problems. RESULTS: Predictors of prolonged postoperative stay were prolonged intensive care unit stay (P < 0.0001), postoperative atrial fibrillation (P = 0.0006), preoperative congestive heart failure (P = 0.002), combined CABG and valve procedure (P = 0.005), prolonged ventilator support (P = 0.01), increasing age (P = 0.012), history of peripheral vascular disease (P = 0.02), and female gender (P = 0.025). The 30-day readmission rate for the early discharge group was 7.8% vs 16.2% for the late discharge group (P = 0.01). The mortality rate for the entire group was 3.3%.

Dependency of contractile reserve on myocardial blood flow: implications for the assessment of myocardial viability with dobutamine stress echocardiography.

BACKGROUND: Contractile reserve, improvement in contractile function during inotropic stimulation, is a proposed marker of viable myocardium. This study was designed to address, in patients with left ventricular dysfunction due to chronic coronary artery disease, whether contractile reserve depends on myocardial blood flow. METHODS AND RESULTS: We studied 19 patients, at rest and during dobutamine, with 2D echocardiography for regional mechanical function and PET for regional myocardial blood flow ([(15)O]water) and oxygen consumption ([11C]acetate). Of 166 myocardial segments, 21 had normal systolic function, 56 were dysfunctional but contractile reserve-positive, and 89 were dysfunctional and contractile reserve-negative. Myocardial blood flow at rest was lower in contractile reserve-negative (0.41+/-0.18 mL x g(-1) x min(-1)) than in contractile reserve-positive (0.50+/-0.22 mL x g(-1) x min(-1)) and normal segments (0.55+/-0.20 mL x g(-1) x min(-1), P<.009). After dobutamine infusion, blood flow increased less in contractile reserve-negative (0.63+/-0.38 mL x g(-1) x min(-1)) than in contractile reserve-positive (1.28+/-0.65 mL x g(-1) x min(-1)) and normal segments (1.93+/-0.83 mL x g(-1) x min(-1), P<.0001). Likewise, myocardial oxygen consumption was lower at rest in contractile reserve-negative (clearance rate of [11C]acetate, 0.043+/-0.012 min(-1)) than in contractile reserve-positive (0.048+/-0.01 min(-1)) and normal segments (0.058+/-0.008 min(-1), P<.02). Myocardial oxygen consumption with dobutamine increased less in contractile reserve-negative (0.060+/-0.013 min(-1)) than in contractile reserve-positive (0.077+/-0.016 min(-1)) and normal segments (0.092+/-0.024 min(-1), P<.0001). Of segments defined as viable by PET, 54% were contractile reserve-negative and exhibited lower blood flow with dobutamine (0.72+/-0.36 mL x g(-1) x min(-1)) than with viable, contractile reserve-positive segments (1.29+/-0.70 mL x g(-1) x min(-1), P<.0001). CONCLUSIONS: Contractile reserve depends, in part, on the level of myocardial blood flow at rest and during inotropic stimulation.

Intraoperative transesophageal echocardiography and epiaortic ultrasound for assessment of atherosclerosis of the thoracic aorta.

OBJECTIVES: This study sought to determine the role of transesophageal echocardiography (TEE) and epiaortic ultrasound in the detection of atherosclerosis of the ascending aorta in patients undergoing cardiac surgery. BACKGROUND: Atherosclerosis of the ascending aorta is a major risk factor for perioperative stroke and systemic embolism in patients undergoing cardiac surgery. METHODS: Forty-four patients underwent prospective evaluation of the ascending aorta with two ultrasound techniques-epiaortic ultrasound and biplane TEE-and by palpation. The severity of atherosclerosis was graded on a four-point scale as normal, mild, moderate or severe. RESULTS: A comparison of results with biplane TEE and those with epiaortic ultrasound yielded a kappa value of 0.12 (95% confidence interval 0 to 0.25), indicating poor correlation between the two. Compared with epiaortic ultrasound, biplane TEE significantly underestimated the severity of ascending aortic atherosclerosis, and this underestimation was more marked in the distal ascending aorta (p < 0.0001). When compared with epiaortic ultrasound and biplane TEE, palpation of the ascending aorta significantly underestimated the presence and severity of atherosclerosis (p < 0.0001 for both). CONCLUSIONS: Epiaortic ultrasound is more accurate than TEE for identification of atherosclerosis of the ascending aorta, but both ultrasound techniques are superior to palpation. Epiaortic ultrasound and TEE provide complementary information regarding thoracic aortic atherosclerosis. Modification of surgical technique on the basis of results of intraoperative epiaortic ultrasound and TEE in elderly patients undergoing cardiac procedures may prevent atheroembolic complications.

Right ventricular dysfunction in low output syndrome after cardiac operations: assessment by transesophageal echocardiography.

BACKGROUND: Low output syndrome after cardiac operations is associated with high morbidity and mortality rates. The contribution of right ventricular dysfunction to this syndrome has not been fully characterized. The purpose of this study was to evaluate the utility of transesophageal echocardiography to identify the frequency and the in-hospital mortality from right ventricular dysfunction in patients with this syndrome. METHODS: Seventy-five consecutive patients undergoing transesophageal echocardiography for low output syndrome early after cardiac operations were evaluated. The findings from transesophageal echocardiography were correlated with the type of surgical procedure, cross-clamp time, right heart hemodynamics, and coronary angiography. RESULTS: Right ventricular systolic dysfunction occurred in 36 patients (42%); in 17 patients it was isolated and in 19 patients it occurred in combination with left ventricular dysfunction. Postoperative right ventricular dysfunction was not uniformly associated with important right coronary artery disease or with prolonged ischemic time during cardiopulmonary bypass. Hemodynamic data were not useful to distinguish the group with postoperative right ventricular dysfunction. Patients with right ventricular dysfunction had a high (44%) in-hospital mortality rate. CONCLUSIONS: Right ventricular dysfunction occurs frequently in patients with low output syndrome after cardiac operations and is associated with a high in-hospital mortality rate. Better understanding of the mechanisms causing postoperative right ventricular dysfunction may provide insight for preventing this complication.

Assessment of myocardial viability by ultrasonic tissue characterization.

In conclusion, myocardial tissue characterization with quantitative ultrasonic indices descriptive of the physical state of the tissue is a promising approach to complement conventional echocardiography in the evaluation of patients with coronary artery disease. In particular, differentiation among hibernating, stunned and scarred myocardium may be possible on the basis of the experience accumulated thus far.

Strategy for the reduction of stroke incidence in cardiac surgical patients.

Atherosclerosis of the ascending aorta (AAA) and severe carotid artery disease are risk factors for stroke in cardiac surgical patients. Twelve hundred of a consecutive series of 1,334 patients 50 years of age or older having a cardiac operation were screened for the presence of AAA by intraoperative ultrasonographic scanning and for the presence of carotid artery occlusive disease (791 of 798 patients > or = 65 years of age and younger symptomatic patients) by carotid duplex scanning. Coronary artery disease was present in 88% of the patients. Patients with moderate or severe AAA (n = 231; 19.3% of the total) were treated by ascending aortic replacement (n = 27) or by modified, less extensive techniques (n = 168) to avoid the atherosclerotic areas. Thirty-three patients had combined carotid endarterectomy and cardiac operation. Thirty-day mortality and stroke rates for the 1,200 patients were 4.0% and 1.6%, respectively. The stroke rate was low (1.1%) among the 969 patients with no or mild AAA. It was zero among 27 patients with moderate or severe AAA who had ascending aortic replacement and among the 33 patients who had carotid endarterectomy. The stroke rates were higher for 111 patients with moderate or severe ascending aortic disease who had only minor interventions (6.3%) and for 16 patients with severe carotid artery disease who did not have carotid endarterectomy (18.7%). Screening for AAA and carotid artery disease and aggressive surgical treatment of moderate or severe AAA and severe or symptomatic carotid artery disease appears to reduce the frequency of stroke in older cardiac surgical patients.