Latent infective endocarditis: epidemiology and clinical characteristics of patients with unsuspected endocarditis detected after elective valve replacement.

BACKGROUND: The diagnosis of infective endocarditis is usually made on the basis of clinical and laboratory criteria and may be confirmed by histologic examination or culture of excised valves. We tried to determine the incidence and significance of inflammatory changes in valves excised during operations for reasons other than infective endocarditis. METHODS: The charts and histopathology of all patients undergoing valve replacement during a 10-year period (1993-2002) were reviewed. A total of 868 patients underwent a total of 970 valve replacements during this period, of whom 11 patients (1.3%) were for endocarditis, with the remaining 857 (98.7%) for other indications. All excised valves were cultured and examined histologically for the presence of inflammatory infiltrates, vegetations, and microorganisms. RESULTS: In 8 of 857 patients (0.9%), the histologic examination unexpectedly demonstrated an infiltrate suggestive of endocarditis. Blood and valve cultures, and serologic tests for Mycoplasma, Chlamydia, Legionella, Q fever, Brucella, Rickettsiae, VDRL, and Bartonella were negative in all but 1 patient, who was found to have Q fever. All received a prolonged course of antibiotics. Six patients had an uneventful recovery; 1 had intramyocardial abscesses and expired during cardiac reoperation; and 1 had recurrent fever and dehiscence of the aortic and mitral valve prostheses and after two cardiac reoperations remains in severe heart failure. CONCLUSIONS: The presence of an unexpected inflammatory infiltrate in heart valves excised for reasons other than endocarditis may occur in 0.9% of such operations; these infiltrates could indicate presence of endocarditis. A microbial origin should be sought, and patients should receive empiric antibiotic treatment for endocarditis.

Aortic valve replacement under deep hypothermic circulatory arrest.

BACKGROUND: Aortic valve replacement (AVR) in the presence of a calcified aorta or patent grafts may preclude clamping of the ascending aorta. We employed deep hypothermic circulatory arrest in order to circumvent this problem. METHODS: Between January 1993 and December 2000, 415 patients underwent AVR in our department. Eight of these were operated using deep hypothermic circulatory arrest. There were 5 males, and mean age was 72 years (range 56-81). Indications for using circulatory arrest were reoperation with patent grafts and/or severe calcification of the ascending aorta. In six patients, cardiopulmonary bypass was achieved via femoro-femoral bypass, and in two via aortic-right atrial cannulation. Retrograde cerebral perfusion was employed in five. Mean bypass time was 155 minutes (range 122-187), and mean circulatory arrest time was 38 minutes (range 31-49). RESULTS: There was no operative mortality, and no patient suffered any neurologic sequelae. Echocardiography showed all valves to be functioning well. CONCLUSIONS: AVR under deep hypothermic circulatory arrest can be accomplished with an acceptable degree of safety. It should be considered as an alternative in patients in whom aortic clamping is prohibitive, and might otherwise be considered inoperable. The ability to connect the patient to bypass and the presence of a "window" to allow aortotomy are prerequisites for employing this method.

Does coronary endarterectomy increase the risk of coronary bypass?

BACKGROUND: With increased incidence of angioplasty and stent implantation, patients referred for coronary bypass (CABG) typically have more advanced and diffuse coronary disease. Thus, more patients may require endarterectomy in order to achieve complete revascularization. We compared our results in patients undergoing CABG with or without coronary endarterectomy. METHODS: Between 1993 and 1999, 2372 patients underwent isolated CABG in our department. A retrospective analysis was performed to compare patients requiring coronary endarterectomy of the LAD (group 1, n = 88), endarterectomy of arteries other than the LAD (group 2, n = 143), to those not requiring endarterectomy (group 3, n = 2071). Patients undergoing CABG without the use of cardiopulmonary bypass were excluded. Group 1 had a higher incidence of proximal LAD stenosis (p = 0.001) than group 3, while group 2 had a higher incidence of peripheral vascular disease (p = 0.02), preoperative MI (p = 0.03) and LV dysfunction (p = 0.001). RESULTS: Operative mortality was 10% in group 1 (p < 0.001) and 4% in group 2 (p = NS) compared to 3% in group 3. Incidence of perioperative MI was 12% in group 1 (p = 0.001) and 8% in group 2 (p = 0.001) compared to 2% in group 3. CONCLUSIONS: Patients requiring endarterectomy of the LAD are at increased risk of operative mortality. This was not true for patients requiring endarterectomy of arteries other than the LAD. In both groups there was an increased risk of perioperative myocardial infarction.