Single-center experience and evolution of technique with the E-vita Open prosthesis.

BACKGROUND: We report our experience in aortic arch repair with the E-vita Open hybrid prosthesis and describe the changes in our technique over time. METHODS: Between October 2013 and December 2019, 56 patients underwent a total aortic arch replacement with the E-vita Open hybrid prosthesis. The main indications were thoracic aorta aneurysm (n = 27) and acute type A aortic dissection (n = 18). We analyze the technique and results in the overall series, and compare both between our early (group I, 25 patients) and late experience (group II, 31 patients). RESULTS: Overall in-hospital mortality was 7.1% (n = 4), and permanent stroke and spinal cord injury were 3.6% and 1.8%, respectively. Fifteen patients (26.8%) underwent a planned second procedure on the distal aorta: 13 endovascular, 1 open, and 1 hybrid. Survival at 1 and 3 years was 90.7% and 80.7%, respectively. Group II included more patients with acute dissection (45.2% vs 16%, P = .02), higher rates of bilateral cerebral perfusion (100% vs 64%, P < .001), left subclavian artery perfusion during lower body circulatory arrest (87.1% vs 0%, P < .001), early reperfusion (96.8% vs 40%, P < .001), and zone 0 to 2 distal anastomosis (100% vs 72%, P = .02). In-hospital mortality (3.2% vs 12%) and permanent stroke (0% vs 8%) tended to be lower in group II. CONCLUSIONS: Total arch replacement with E-vita Open hybrid prosthesis in complex thoracic aorta disease is safe. One-stage treatment is feasible when pathology does not extend beyond the proximal descending thoracic aorta. In any case, it facilitates subsequent procedures on distal aorta if needed.

Reoperation for composite valve graft failure: Operative results and midterm survival.

BACKGROUND AND AIM OF THE STUDY: The replacement of a failed composite valve graft is technically more demanding and is associated with increased morbidity and mortality. We present our technique and outcomes for reoperations for composite graft failures. METHODS: Between September 2011 and June 2017, 14 patients underwent a redo composite graft replacement. Twelve patients (85.7%) were male, and mean age was 58.4 years ± 12 standard deviation (SD). One patient had two previous root replacements. Indications for reoperation were endocarditis (8), aortic pseudoaneurysm (3), and aortic prosthesis thrombosis (3). Mean logistic EuroSCORE and EuroSCORE II were 30.8% and 14.7%, respectively. RESULTS: A mechanical composite graft was used in 12 patients and biological composite grafts were used in two patients. Hospital mortality was 14.3% (n = 2). One patient (7.1%) required reoperation for bleeding, One patient (7.1%) had mechanical ventilation >24 h, and four patients (28.6%) required implantation of a permanent pacemaker. Median intensive care unit and hospital stays were 3 days (interquartile range [IQR] 1-5) and 10 days (IQR 6.5-38.5). One patient experienced recurrent prosthetic valve endocarditis 14 months after operation. On follow-up, 11 of 12 survivors were in New York Heart Association class I or II. Survival at 3 years was 85.7% ± 9.4% SD. CONCLUSIONS: Composite valve graft replacement can be performed with acceptable morbidity and mortality with good mid-term survival.

Off-Pump to On-Pump Emergency Conversion: Incidence, Risk Factors, and Impact on Short- and Long-Term Results.

BACKGROUND AND AIM OF THE STUDY: Emergency conversion to on-pump during off-pump coronary artery bypass surgery (CABG) increases morbidity and mortality. We analyze its risk factors and impact on short- and long-term outcomes. METHODS: All patients undergoing isolated CABG between 2006 and 2012 were included. Postoperative and midterm mortality and the combined event (death, myocardial infarction, cerebrovascular accident, and repeat revascularization) were compared between patients with and without conversion. Multivariate analysis and propensity score matching were performed. RESULTS: A total of 1268 patients were operated off pump and 37 patients required an emergency conversion. Postoperative death and combined event were more frequent among patients who were converted (31.6% vs. 3.31%, p < 0.001 and 43.2% vs. 11.5%, p < 0.001, respectively). Conversion was an independent predictor of both events (OR = 6.22, 95%CI: 2.01 to 19.3 and OR = 5.06, 95%CI: 2.41 to 10.61, respectively). Mean follow-up was 32.5 months. At four years, survival and freedom from the combined event was poorer for conversion (75% vs. 88%, p < 0.001 and 50% vs. 79%, p < 0.001, respectively). Conversion was an independent predictor for late mortality (HR = 2.4, 95%CI: 1.1 to 5.22) and the risk of combined event (HR = 2.97, 95%CI: 1.79 to 4.91). A 3:1 propensity score matching analysis was performed: conversion increased both perioperative and four-year mortality (12.6% vs. 4.5%, p < 0.001 and 25% vs. 12%, p = 0.007); and early and late incidence of the combined event (43.2% vs. 11.7%, p < 0.001 and 53% vs. 24%, p = 0.001). Preoperative atrial fibrillation and previous percutaneous coronary intervention were independent predictors of conversion. CONCLUSIONS: Emergency conversion from off- to on-pump CABG dramatically worsens early and late outcomes. Previous percutaneous coronary intervention and atrial fibrillation increase the risk of conversion.

Age-dependent defective TGF-beta1 signaling in patients undergoing coronary artery bypass grafting.

BACKGROUND: Transforming growth factor beta (TGF-ß1) is a pleiotropic cytokine, which is deregulated in atherosclerosis; however the role of age in this process is unknown. We aimed to assess whether TGF-ß1 signaling is affected by age. METHODS: Vascular smooth muscle cells (VSMC) were obtained from patients undergoing abdominal surgery. Levels of TGF-ß1 were measured by ELISA in sera from 169 patients undergoing coronary artery bypass grafting (CABG). The p27 expression was determined by Western blot from internal mammary arteries (IMA) obtained from CABG patients (n=13). In VSMC from these patients undergoing abdominal surgery, secretion of TGF-ß1 was determined by ELISA of cell-conditioned media. RESULTS: In VSMC from aged patients we observed a lower TGF-ß1 secretion, measured as TGF-ß1 concentration in cell conditioned medium (p<0.001). This effect was correlated to an age-dependent decrease of p27 expression in IMA from aged CABG patients. In a similar manner, there was an age-dependent decrease of serum TGF-ß1 levels in CABG patients (p=0.0195). CONCLUSIONS: VSMC from aged patients showed a higher degree of cellular senescence and it was associated to a lower TGF-ß1 secretion and signaling.

Relationship between serum levels of triglycerides and vascular inflammation, measured as COX-2, in arteries from diabetic patients: a translational study.

BACKGROUND: Inflammation is a common feature in the majority of cardiovascular disease, including Diabetes Mellitus (DM). Levels of pro-inflammatory markers have been found in increasing levels in serum from diabetic patients (DP). Moreover, levels of Cyclooxygenase-2 (COX-2) are increased in coronary arteries from DP. METHODS: Through a cross-sectional design, patients who underwent CABG were recruited. Vascular smooth muscle cells (VSMC) were cultured and COX-2 was measured by western blot. Biochemical and clinical data were collected from the medical record and by blood testing. COX-2 expression was analyzed in internal mammary artery cross-sections by confocal microscopy. Eventually, PGI2 and PGE2 were assessed from VSMC conditioned media by ELISA. RESULTS: Only a high glucose concentration, but a physiological concentration of triglycerides exposure of cultured human VSMC derived from non-diabetic patients increased COX-2 expression .Diabetic patients showed increasing serum levels of glucose, Hb1ac and triglycerides. The bivariate analysis of the variables showed that triglycerides was positively correlated with the expression of COX-2 in internal mammary arteries from patients (r(2) = 0.214, P < 0.04). CONCLUSIONS: We conclude that is not the glucose blood levels but the triglycerides levels what increases the expression of COX-2 in arteries from DP.

Decreased pre-surgical CD34+/CD144+ cell number in patients undergoing coronary artery bypass grafting compared to coronary artery disease-free valvular patients.

BACKGROUND: Cardiovascular disease has been linked to endothelial progenitor cell (EPC) depletion and functional impairment in atherosclerosis and aortic stenosis. EPCs may play a pivotal role in vascular grafting. However, the EPC depletion in coronary artery bypass grafting (CABG) patients has not been compared to coronary artery disease-free valvular replacement patients with aortic stenosis. METHODS: We aimed to assess the basal number of CD34+/KDR+ and CD34+/CD144+ cells in CABG patients, compared to aortic stenosis valvular replacement patients. 100 patients (51 CABG and 49 valvular surgery ones) were included in the present study. All CABG or valvular patients had angiographic demonstration of the presence or the absence of coronary artery disease, respectively. Numbers of CD34+/KDR+ and CD34+/CD144+ were assessed by flow cytometry of pre-surgical blood samples. RESULTS: We found a lower number of CD34+/CD144+ cells in CABG patients compared to valvular patients (0.21 ± 0.03% vs. 0.47 ± 0.08%), and this difference remained statistically significant after the P was adjusted for multiple comparisons (P = 0.01428). Both groups had more EPCs than healthy controls. CONCLUSIONS: Pre-surgical CD34+/CD144+ numbers are decreased in CABG patients, compared to valvular patients with absence of coronary disease.

Early recurrence is a predictor of late failure in surgical ablation of atrial fibrillation.

We sought to determine if early recurrence of atrial fibrillation (AF) after surgical ablation is a risk factor of late failure. Between February 2004 to May 2009, 106 patients underwent surgical ablation of concomitant permanent AF with radiofrequency. Operations primarily consisted of valve surgery in 85% of patients. Hospital mortality was 2.8% (n = 3). The median follow-up was 37 months (interquartile rank 12-77), and was complete in 99% of patients. Freedom from AF was 82%, 76% and 68% at one, two and three years, respectively. Patients with early recurrence of AF had less prevalence of sinus rhythm in late follow-up (P < 0.001). Multivariate Cox regression analysis showed that AF duration [hazard ratio (HR) 1.014, 95% CI 1.009-1.020, P < 0.001] and early recurrence of AF (HR 3.45, 95% CI 1.50-7.95, P = 0.004) were independent risk factors for failure. In conclusion, in our series, early recurrence of AF after surgical ablation is a strong predictor of late failure.

Adhesión de células progenitoras endoteliales humanas a arterias humanas de pacientes diabéticos y no diabéticos: efecto de la pioglitazona / Differential adhesion of human endothelial progenitor cells to human arteries from diabetic and non-diabetic patients: effect of pioglitazone

Introducción La disfunción endotelial es un importante mediador de la mayor morbimortalidad cardiovascular de los pacientes diabéticos. Las células progenitoras endoteliales (EPC) parecen poseer defectos funcionales en estos pacientes. La pioglitazona aumenta el número y función de las EPC y disminuye la mortalidad cardiovascular en la población diabética. Objetivos Determinar la capacidad de adhesión de EPC cultivadas sobre arterias de pacientes diabéticos y no diabéticos, así como evaluar los efectos de la glucosa y la pioglitazona sobre estos parámetros. Material y métodos Las EPC se aislaron de células mononucleares a partir de la capa leucoplaquetaria de sangre de donantes y se cultivaron sobre fibronectina en medio microvascular. La adhesión se midió marcando las células con 111In-oxina y pasándolas ex vivo sobre una cámara de flujo con arterias mamarias internas remanentes de cirugía cardiaca. La expresión de la proteína CXCR-4 se determinó por citometría de flujo. Resultados Se observó una mayor adhesión de las EPC sobre las arterias de pacientes diabéticos. Esta adhesión disminuyó al incubar las células con glucosa a 15mM. La co-incubación con pioglitazona 1μM restauró la capacidad adhesiva de las EPC. La glucosa a 15mM disminuyó la expresión de CXCR-4 en las EPC cultivadas, en cambio, la pioglitazona a 1μM fue capaz de aumentarla. Conclusión Pese a que las arterias de pacientes diabéticos tienen una mayor capacidad de reclutar EPC, la hiperglucemia disminuye las propiedades adhesivas de estas células (AU)

Introduction Endothelial dysfunction underlies the increased cardiovascular disease burden in diabetic patients. Endothelial progenitor cell (EPC) function seems to be defective in these patients. Pioglitazone has been shown to improve the number and function of EPCs and to decrease cardiovascular mortality in the diabetic population. Objective To determine the adhesive capacity of cultured EPCs on arteries from diabetic and non-diabetic patients and evaluate the effects of high glucose and pioglitazone on this parameter. Material and methods EPCs were isolated from mononuclear cells from buffy coats, obtained from healthy blood donors. The cells were plated on fibronectin and were cultured in a microvascular medium. EPCs were labelled with 111In-oxine and adhesion was assessed using a flow chamber in which internal mammary arteries obtained from cardiac surgery (..) (AU)

Role of TGF-beta1 and MAP kinases in the antiproliferative effect of aspirin in human vascular smooth muscle cells.

BACKGROUND: We aimed to test the antiproliferative effect of acetylsalicylic acid (ASA) on vascular smooth muscle cells (VSMC) from bypass surgery patients and the role of transforming growth factor beta 1 (TGF-beta1). METHODOLOGY/PRINCIPAL FINDINGS: VSMC were isolated from remaining internal mammary artery from patients who underwent bypass surgery. Cell proliferation and DNA fragmentation were assessed by ELISA. Protein expression was assessed by Western blot. ASA inhibited BrdU incorporation at 2 mM. Anti-TGF-beta1 was able to reverse this effect. ASA (2 mM) induced TGF-beta1 secretion; however it was unable to induce Smad activation. ASA increased p38(MAPK) phosphorylation in a TGF-beta1-independent manner. Anti-CD105 (endoglin) was unable to reverse the antiproliferative effect of ASA. Pre-surgical serum levels of TGF-beta1 in patients who took at antiplatelet doses ASA were assessed by ELISA and remained unchanged. CONCLUSIONS/SIGNIFICANCE: In vitro antiproliferative effects of aspirin (at antiinflammatory concentration) on human VSMC obtained from bypass patients are mediated by TGF-beta1 and p38(MAPK). Pre-surgical serum levels of TGF- beta1 from bypass patients who took aspirin at antiplatelet doses did not change.

EPC adhesion to arteries from diabetic and non-diabetic patients: effect of pioglitazone.

Endothelial progenitor cell (EPC) dysfunction is an important mediator of vascular disease in diabetes. We aimed to elucidate the mechanism of adhesion of EPC to diabetic and non-diabetic arteries and to study the effect of the anti-diabetic drug pioglitazone. Peripheral blood mononuclear cells were isolated from healthy donors. Human internal mammary arteries (HIMA) were isolated from patients who underwent coronary artery bypass surgery. EPC were labelled with 111In-oxine and perfused to HIMA in a perfusion chamber. Stromal derived factor-1 (SDF-1) and cyclooxygenase-2 (COX-2) were assessed by immunohistochemical analysis. CXCR-4 expression was assessed by flow cytometry. Adhesion of EPC was increased in HIMA from diabetic patients and was reduced after preincubation with 15 mM glucose for 72 h. EPC adhesion and CXCR-4 expression were inversely correlated. COX-2 and SDF-1 immunostaining in HIMA were positively correlated. Pioglitazone (1 microM) increased the adhesion of EPC to HIMA and the expression of CXCR-4 in EPC. Therefore, EPC-recruiting capability is increased in diabetic arteries, although EPC adhesion is notably impaired by high glucose concentrations. Interestingly, pioglitazone treatment enhances EPC adhesiveness.

[Absence of a relationship between surgical volume and mortality in cardiac surgery units in Spain]. / No hay relación entre el volumen quirúrgico y la mortalidad en los servicios de cirugía cardiaca en España.

INTRODUCTION AND OBJECTIVES: The relationship between the annual number of cardiac procedures at a particular center (i.e., volume) and surgical outcome is controversial. Several studies in western countries indicate that there is an inverse relationship between surgical volume and mortality. We studied the number of procedures carried out at several cardiac surgery units in Spain and their relationship to overall and risk-adjusted mortality. METHODS: This prospective observational study carried out in 6054 patients undergoing cardiac surgery at 16 hospitals represents 34% of all cardiac surgery performed in Spain during 2004. Data on risk factors and outcomes for each patient treated at participating institutions were analyzed. Data from each center were checked by an external referee. Surgical risk was evaluated for each patient using the Parsonnet and EuroSCORE methods, with the aim of determining risk-adjusted mortality. RESULTS: Overall mortality was 7.7% (95% confidence interval, 7.0%-8.4%). The risk-adjusted mortality index was calculated to be 0.81 using the Parsonnet method, and 1.12 using EuroSCORE. The Pearson correlation coefficient for the relationship between the number of procedures carried out at a center and mortality was 0.065 for overall mortality, 0.092 for risk-adjusted mortality (Parsonnet method), and 0.111 for risk-adjusted mortality (EuroSCORE method). After discarding data from the two centers with highest and lowest mortality rates, respectively, the correlations were -0.464, -0.420 and -0.267, respectively. CONCLUSIONS: No statistically significant relationship was found between the number of cardiac procedures carried out at a particular center in Spain and inhospital mortality.

No hay relación entre el volumen quirúrgico y la mortalidad en los servicios de cirugía cardiaca en España / Absence of a relationship between surgical volume and mortality in cardiac surgery units in Spain

Introducción y objetivos. La relación entre el número de intervenciones cardiacas anuales (volumen) de un centro y sus resultados es controvertido. Varios estudios occidentales hallan una relación inversa volumen/mortalidad. Analizamos el número de intervenciones de algunos centros cardioquirúrgicos nacionales y su mortalidad bruta y ajustada a riesgo. Métodos. Estudio observacional prospectivo de 6.054 pacientes intervenidos en 16 hospitales, correspondientes al 34% del total de la actividad cardioquirúrgica que se realizó en España durante el año 2004. Se analizaron los factores de riesgo y los resultados de cada paciente intervenido en los centros participantes. Los datos de cada centro fueron verificados por auditoría independiente. Se estimó el riesgo quirúrgico de cada paciente intervenido por los métodos de Parsonnet y EuroSCORE, con objeto de evaluar la mortalidad ajustada a riesgo. Resultados. La mortalidad total fue del 7,7% (intervalo de confianza del 95%, 7%-8,4%). El índice de mortalidad ajustada a riesgo fue 0,81 por el método de Parsonnet y 1,12 por EuroSCORE. La correlación entre número de cirugías de un centro y mortalidad por el método de Pearson fue 0,065 para la mortalidad bruta, 0,092 para la mortalidad ajustada a riesgo por Parsonnet y 0,111 para la mortalidad ajustada por EuroSCORE. Descartando los centros con mortalidades más alta y más baja, los resultados fueron ­0,464, ­0,420 y ­0,267 respectivamente. Conclusiones. En España no hay relación estadísticamente significativa entre el número de intervenciones cardiacas de un centro y su mortalidad hospitalaria

Introduction and objectives. The relationship between the annual number of cardiac procedures at a particular center (i.e., volume) and surgical outcome is controversial. Several studies in western countries indicate that there is an inverse relationship between surgical volume and mortality. We studied the number of procedures carried out at several cardiac surgery units in Spain and their relationship to overall and risk-adjusted mortality. Methods. This prospective observational study carried out in 6054 patients undergoing cardiac surgery at 16 hospitals represents 34% of all cardiac surgery performed in Spain during 2004. Data on risk factors and outcomes for each patient treated at participating institutions were analyzed. Data from each center were checked by an external referee. Surgical risk was evaluated for each patient using the Parsonnet and EuroSCORE methods, with the aim of determining risk-adjusted mortality. Results. Overall mortality was 7.7% (95% confidence interval, 7.0%­8.4%). The risk-adjusted mortality index was calculated to be 0.81 using the Parsonnet method, and 1.12 using EuroSCORE. The Pearson correlation coefficient for the relationship between the number of procedures carried out at a center and mortality was 0.065 for overall mortality, 0.092 for risk-adjusted mortality (Parsonnet method), and 0.111 for risk-adjusted mortality (EuroSCORE method). After discarding data from the two centers with highest and lowest mortality rates, respectively, the correlations were ­0.464, ­0.420 and ­0.267, respectively. Conclusions. No statistically significant relationship was found between the number of cardiac procedures carried out at a particular center in Spain and inhospital mortality

Expresión de COX-2 en arterias y células vasculares de pacientes diabéticos y no diabéticos / COX-2 expression in arteries and vascular cells from diabetic and nondiabetic patients

Introducción. El objetivo de este trabajo fue estudiar la expresión de ciclooxigenasa 2 (COX-2) en arterias y células de músculo liso vascular provenientes de pacientes diabéticos y no diabéticos, así como su inducción tras incubar células de pacientes no diabéticos con un preparado de triglicéridos. Material y métodos. Se utilizaron segmentos de arterias mamarias internas usadas en cirugía de revascularización coronaria, y se procedió a homogeneizarlos, fijarlos o cultivarlos para obtener células de músculo liso vascular. La expresión de COX-2 se analizó por Western blot y microscopia confocal. Para inducir in vitro la expresión de COX-2, se incubaron las células de pacientes no diabéticos con Intralipid®. Resultados. Todas las medidas indicaron una mayor expresión de COX-2 tanto en arterias como en células de pacientes diabéticos. La expresión de COX-2 se correlacionó con el índice EuroSCORE, como índice pronóstico de mortalidad precoz y de complicaciones mayores en la cirugía coronaria, menos favorable. Asimismo, la expresión de COX-2 se incrementó de forma significativa con concentraciones crecientes de Intralipid®. Conclusiones. La expresión de COX-2 en arterias mamarias internas se relaciona con la diabetes mellitus y un índice EuroSCORE más desfavorable. También es posible aumentar la expresión de COX-2 incubando las células de pacientes no diabéticos con triglicéridos, lo que refuerza la asociación entre hipertrigliceridemia, diabetes tipo 2, inflamación vascular y un peor pronóstico clínico (AU)

Introduction. The aim of this study was to investigate cyclooxygenase (COX)-2 expression in arteries and vascular smooth muscle cells from diabetic and nondiabetic patients. A further aim was to analyze COX-2 induction after cells from nondiabetic patients were incubated with a triglyceride-rich solution. Matherial and methods. Segments from internal mammary arteries discarded after coronary artery bypass grafting were used. Arterial segments were homogenized, fixed, or prepared for vascular smooth muscle cell cultures. COX-2 expression was assessed by both Western blot and confocal microscopy. For in vitro induction of COX-2 expression, cells from nondiabetic patients were incubated with Intralipid®. Results. All measurements showed increased COX-2 expression in the arteries and cells from diabetic patients. COX-2 expression was correlated with a poorer prognosis measured by the EuroSCORE scale. In addition, COX-2 expression was significantly enhanced when cells were incubated with increasing Intralipid® concentrations. Conclusions. COX-2 expression in internal mammary arteries is related to type 2 diabetes and a poorer EuroSCORE. In addition, COX-2 expression was experimentally increased when cells from nondiabetic patients were incubated with triglycerides, which enhances the associations among hypertriglyceridemia, type 2 diabetes, vascular inflammation, and a poorer clinical prognosis (AU)

Human vascular smooth muscle cells from diabetic patients are resistant to induced apoptosis due to high Bcl-2 expression.

An emerging body of evidence suggests that vascular remodeling in diabetic patients involves a perturbation of the balance between cell proliferation and cell death. Our aim was to study whether arteries and vascular smooth muscle cells (VSMCs) isolated from diabetic patients exhibit resistance to apoptosis induced by several stimuli. Internal mammary arteries (IMAs) were obtained from patients who had undergone coronary artery bypass graft surgery. Arteries from diabetic patients showed increasing levels of Bcl-2 expression in the media layer, measured by immunofluorescence and by Western blotting. Human IMA VSMCs from diabetic patients showed resistance to apoptosis, measured as DNA fragmentation and caspase-3 activation, induced by C-reactive protein (CRP) and other stimuli, such as hydrogen peroxide and 7beta-hydroxycholesterol. The diabetic cells also exhibited overexpression of Bcl-2. Knockdown of Bcl-2 expression with Bcl-2 siRNA in cells from diabetic patients reversed the resistance to induced apoptosis. Consistent with the above, we found that pretreatment of nondiabetic VSMCs with high glucose abolished the degradation of Bcl-2 induced by CRP. Moreover, cell proliferation was increased in diabetic compared with nondiabetic cells. This differential effect was potentiated by glucose. We conclude that the data provide strong evidence that arterial remodeling in diabetic patients results from a combination of decreased apoptosis and increased proliferation.

Chlamydia pneumoniae in the atherosclerotic plaques of patients with unstable angina undergoing coronary artery bypass grafting: does it have prognostic implications?

OBJECTIVE: This study sought to evaluate the prognostic significance of the presence of DNA of Chlamydia pneumoniae in the coronary atherosclerotic lesions of patients with unstable angina. BACKGROUND: C. pneumoniae has been implicated in the pathogenesis of coronary artery disease by serological and pathological studies, but whether antichlamydial antibodies and the presence of this pathogen in the coronary atherosclerotic tissue are related to prognosis in unstable angina remains unclear. METHODS: A total 76 coronary specimens from 45 patients with unstable angina undergoing bypass surgery were subjected to nested polymerase chain reaction (PCR) for C. pneumoniae. Antichlamydial immunoglobulin G (IgG), A (IgA) and M (IgM) were also examined by an enzyme immunoassay. Patients were followed during a 2-year period to determine the incidence of adverse cardiovascular events. RESULTS: DNA of C. pneumoniae was detected in 57 (75%) of 76 atherosclerotic lesions: 39 patients showed a positive PCR result in at least one plaque. Of the 45 patients, 44 (97.7%) showed a positive serological result: IgG was positive in 39 (86.6%) patients, IgM in five (11.1%) patients and IgA in 42 (93.3%). Clinical characteristics and serologic results were similarly distributed in patients with and without infected lesions at enrollment. At least one adverse event occurred in 21 (46.6%) of the 45 patients at 2 years: death in nine (20%), recurrent angina in 12 (26.6%), revascularization in six (13.3%) and myocardial infarction in two (4.4%) patients. The composite endpoint of death, myocardial infarction, recurrent angina and revascularization at 2-year follow-up did not differ according to the PCR or serologic results. CONCLUSIONS: The presence of C. pneumoniae in coronary atherosclerotic plaques of patients with unstable angina undergoing coronary bypass grafting does not have prognostic significance. In addition, serology does not allow us to differentiate those patients with plaque infection by C. pneumoniae and also does not provide any prognostic information in these patients.