A pragmatic approach for mortality prediction after surgery in infective endocarditis: optimizing and refining EuroSCORE.

OBJECTIVE: To simplify and optimize the ability of EuroSCORE I and II to predict early mortality after surgery for infective endocarditis (IE). METHODS: Multicentre retrospective study (n = 775). Simplified scores, eliminating irrelevant variables, and new specific scores, adding specific IE variables, were created. The performance of the original, recalibrated and specific EuroSCOREs was assessed by Brier score, C-statistic and calibration plot in bootstrap samples. The Net Reclassification Index was quantified. RESULTS: Recalibrated scores including age, previous cardiac surgery, critical preoperative state, New York Heart Association >I, and emergent surgery (EuroSCORE I and II); renal failure and pulmonary hypertension (EuroSCORE I); and urgent surgery (EuroSCORE II) performed better than the original EuroSCOREs (Brier original and recalibrated: EuroSCORE I: 0.1770 and 0.1667; EuroSCORE II: 0.2307 and 0.1680). Performance improved with the addition of fistula, staphylococci and mitral location (EuroSCORE I and II) (Brier specific: EuroSCORE I 0.1587, EuroSCORE II 0.1592). Discrimination improved in specific models (C-statistic original, recalibrated and specific: EuroSCORE I: 0.7340, 0.7471 and 0.7728; EuroSCORE II: 0.7442, 0.7423 and 0.7700). Calibration improved in both EuroSCORE I models (intercept 0.295, slope 0.829 (original); intercept -0.094, slope 0.888 (recalibrated); intercept -0.059, slope 0.925 (specific)) but only in specific EuroSCORE II model (intercept 2.554, slope 1.114 (original); intercept -0.260, slope 0.703 (recalibrated); intercept -0.053, slope 0.930 (specific)). Net Reclassification Index was 5.1% and 20.3% for the specific EuroSCORE I and II. CONCLUSIONS: The use of simplified EuroSCORE I and EuroSCORE II models in IE with the addition of specific variables may lead to simpler and more accurate models.

International experts' practice in the antibiotic therapy of infective endocarditis is not following the guidelines.

OBJECTIVE: The management of infective endocarditis (IE) may differ from international guidelines, even in reference centres. This is probably because most recommendations are not based on hard evidence, so the consensus obtained for the guidelines does not represent actual practices. For this reason, we aimed to evaluate this question in the particular field of antibiotic therapy. METHODS: Thirteen international centres specialized in the management of IE were selected, according to their reputation, clinical results, original research publications and quotations. They were asked to detail their actual practice in terms of IE antibiotic treatment in various bacteriological and clinical situations. They were also asked to declare their IE-related in-hospital mortality for the year 2015. RESULTS: The global compliance with guidelines concerning antibiotic therapy was 58%, revealing the differences between theoretical 'consensus', local recommendations and actual practice. Some conflicts of interest were also probably expressed. The adherence to guidelines was 100% when the protocol was simple, and decreased with the seriousness of the situation (Staphylococus spp. 54%-62%) or in blood-culture-negative endocarditis (0%-15%) that requires adaptation to clinical and epidemiological data. CONCLUSION: Worldwide experts in IE management, although the majority of them were involved and co-signed the guidelines, do not follow international consensus guidelines on the particular point of the use of antibiotics.

Cardiac complications during pregnancy are better predicted with the modified WHO risk score.

BACKGROUND/OBJECTIVE: Several risk scores (RSs) have been used to stratify risk of cardiac complications (CCs) in pregnant patients with heart disease. We aimed to compare and contrast the accuracy of several RSs for predicting CC in this population. METHODS: Prospective inclusion of all consecutive pregnant patients with heart disease, and follow-up until 6 months postpartum. CCs were defined as primary if admission was required due to heart failure, arrhythmia or thromboembolic events, and secondary if the decline in NYHA class compared with baseline was >2 or urgent invasive cardiac procedures were needed. The discriminatory power of each RS was assessed by the area-under-the receiver-operating characteristic (ROC) curve (AUC). RESULTS: 179 patients, mean age: 32 years, accounted for 13.4% of CC (primary 11.7%, secondary 1.7%); the main diagnosis was congenital heart disease (CHD) in 68% followed by valvulopathies in 16%, arrhythmia in 7% and myocardiopathies in 5%. 22% (n=40) were classified as mWHO=1, 59% (n=105) mWHO=2 including subgroup 2-3, 14% (n=26) mWHO=3 and 4%(n=7) mWHO=4; 1 patient was unclassifiable. mWHO showed a better AUC (0.763) than CARPREG (0.67). For the CHD population, ZAHARA RS showed an AUC of 0.74, and Khairy an AUC of 0.632. CONCLUSIONS: mWHO was better at predicting CC than CARPREG; mWHO was also better at predicting CC than the specific CHD RS in the CHD subgroup. PRACTICE: There are an increasing number of pregnant women with HD. IMPLICATIONS: Improved prediction of CC risk during pregnancy can provide better preconception assessment in women with HD.

Immediate and long-term outcome of left-sided infective endocarditis. A 12-year prospective study from a contemporary cohort in a referral hospital.

The aim of this study was to describe the immediate and long-term prognosis of a contemporary cohort of patients with left-sided infective endocarditis (LSIE). A prospective observational cohort study was conducted in a referral centre. Between January 2000 and December 2011, all consecutive adult patients with LSIE were followed-up until death, relapse, recurrence, need for late surgery, or last control. During the active phase of IE, 174 of 438 patients underwent surgery (40% overall; 43% native valve (NVIE), 30% prosthetic valve (PVIE)) and 125 died (29% overall; 26% NVIE, 39% PVIE). The median follow-up in survivors was 3.2 years (interquartile range (IQR) 1.0-6.0 years). Relapses occurred in seven patients (2.2%; 95% CI, 1.1-4.5) and recurrences in eight (2.6%; 95% CI, 1.3-5.0), with an incidence density of 0.0067 per patient-year (95% CI, 0.0029-0.0133) and high mortality (75% of recurrences). Only four of 130 survivors (3.1%; 95% CI, 1.2-7.6) who were treated surgically during the active phase of the disease, and 14/183 (7.7%; 95% CI, 4.6-12.4) of those not undergoing surgery needed operation during follow-up (p 0.09). In the 313 survivors, actuarial survival was 86% at 1 year (87% NVIE, 83% PVIE), 79% at 2 years (81% NVIE, 72% PVIE) and 68% at 5 years (71% NVIE, 57% PVIE). At 1 year, 115 of 397 patients (29.0%; 95% CI, 24.7-33.6) remained alive, with no surgery requirement, relapse or recurrence. LSIE is associated with considerable in-hospital and long-term mortality, especially PVIE. However, relapses, recurrences and the need for late surgery are uncommon.

Prognosis of left-sided infective endocarditis in patients transferred to a tertiary-care hospital--prospective analysis of referral bias and influence of inadequate antimicrobial treatment.

The aims of this study were to compare the characteristics of adult patients with left-sided infective endocarditis (LSIE) diagnosed and treated in a tertiary-care hospital with those of patients referred from a second-level community hospital, and to establish the accuracy of diagnosis and adequacy of treatment in referred patients and the influence of this factor on outcome. A prospective observational cohort study was conducted at Hospital Universitari Vall d'Hebron, a 1000-bed teaching hospital in Barcelona (Spain) and a referral centre for cardiac surgery. One hundred and fourteen of 337 (34%) episodes of LSIE treated in our hospital occurred in transferred patients. As compared with patients diagnosed in our hospital, transferred patients acquired LSIE within the healthcare system less often (16.7% vs. 38.1%, p <0.001), were in better health (Charlson index 3 (interquartile range (IQR)) 1-4) vs. 4 (IQR 2-6), p <0.001), had more complications (94.7% vs. 78.9%, p <0.001), underwent more operations (69.3% vs. 22.1%, p <0.001), and experienced similar mortality (22.8% vs. 31.4%, p 0.100). Only 52 of 114 (45.6%) referred patients received an antimicrobial regimen included in the American, European or Spanish guidelines at the hospital of origin. After adjustment for congestive heart failure and staphylococcal infection in multivariate logistic regression, inadequate or no antimicrobial treatment at origin was a risk factor for in-hospital mortality (OR 3.3, 95% CI 1.1-10.0, p 0.030). Errors in the initial antimicrobial treatment prescribed for LSIE are associated with greater mortality.

Therapeutic strategies after coronary stenting in chronically anticoagulated patients: the MUSICA study.

OBJECTIVES: To identify the therapeutic regimens used at discharge in patients receiving oral anticoagulant therapy (OAT) who undergo stenting percutaneous coronary intervention and stent implantation (PCI-S), and to assess the safety and efficacy associated with different therapeutic regimens according to thromboembolic risk. DESIGN: A prospective multicentre registry. SETTING: In hospital, after discharge and follow-up by telephone call. PATIENTS AND METHODS: 405 patients (328 male/77 female; mean (SD) age 71 (9) years) receiving OAT who underwent PCI-S between November 2003 and June 2006 from nine catheterisation laboratories of tertiary care teaching hospitals in Spain and one in the United Kingdom were included. RESULTS: Three therapeutic regimens were identified at discharge: triple therapy (TT) -- that is, any anticoagulant (AC) plus double antiplatelet therapy (DAT; 278 patients (68.6%); AC and a single antiplatelet (AC+AT; 46 (11.4%)) and DAT only (81 (20%)). At 6 months, patients receiving TT showed the greatest rate of bleeding events. No patients receiving DAT at low thromboembolic risk presented a bleeding event (14.8% receiving TT, 11.8% receiving AC+AT and 0% receiving DAT, p = 0.033) or cardiovascular event (6.7% receiving TT, 0% receiving AC+AT and 0% receiving DAT, p = 0.126). The combination of AC+AT showed the worst rate of adverse events in the whole cohort, especially in patients at moderate-high thromboembolic risk. CONCLUSIONS: In patients receiving OAT, TT was the most commonly used regimen after PCI-S. DAT was associated with the lowest rate of bleeding events and a similar efficacy to TT in patients at low thromboembolic risk. TT should probably be restricted to patients at moderate-high thromboembolic risk.

Coagulase-negative staphylococcal prosthetic valve endocarditis--a contemporary update based on the International Collaboration on Endocarditis: prospective cohort study.

OBJECTIVE: To describe the contemporary features of coagulase-negative staphylococcal (CoNS) prosthetic valve endocarditis (PVE). DESIGN: Observational study of prospectively collected data from a multinational cohort of patients with infective endocarditis. Patients with CoNS PVE were compared to patients with Staphylococcus aureus and viridans streptococcal (VGS) PVE. SETTING: The International Collaboration on Endocarditis-Prospective Cohort Study (ICE-PCS) is a contemporary cohort of patients with infective endocarditis from 61 centres in 28 countries. PATIENTS: Adult patients in the ICE-PCS with definite PVE and no history of injecting drug use from June 2000 to August 2005 were included. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Heart failure, intracardiac abscess, death. RESULTS: CoNS caused 16% (n = 86) of 537 cases of definite non-injecting drug use-associated PVE. Nearly one-half (n = 33/69, 48%) of patients with CoNS PVE presented between 60 days and 365 days of valve implantation. The rate of intracardiac abscess was significantly higher in patients with CoNS PVE (38%) than in patients with either S aureus (23%, p = 0.03) or VGS (20%, p = 0.05) PVE. The rate of abscess was particularly high in early (50%) and intermediate (52%) CoNS PVE. In-hospital mortality was 24% for CoNS PVE, 36% for S aureus PVE (p = 0.09) and 9.1% for VGS PVE (p = 0.08). Meticillin resistance was present in 68% of CoNS strains. CONCLUSIONS: Nearly one-half of CoNS PVE cases occur between 60 days and 365 days of prosthetic valve implantation. CoNS PVE is associated with a high rate of meticillin resistance and significant valvular complications.

Candida infective endocarditis.

Candida infective endocarditis (IE) is uncommon but often fatal. Most epidemiologic data are derived from small case series or case reports. This study was conducted to explore the epidemiology, treatment patterns, and outcomes of patients with Candida IE. We compared 33 Candida IE cases to 2,716 patients with non-fungal IE in the International Collaboration on Endocarditis-Prospective Cohort Study (ICE-PCS). Patients were enrolled and the data collected from June 2000 until August 2005. We noted that patients with Candida IE were more likely to have prosthetic valves (p < 0.001), short-term indwelling catheters (p < 0.0001), and have healthcare-associated infections (p < 0.001). The reasons for surgery differed between the two groups: myocardial abscess (46.7% vs. 22.2%, p = 0.026) and persistent positive blood cultures (33.3% vs. 9.9%, p = 0.003) were more common among those with Candida IE. Mortality at discharge was higher in patients with Candida IE (30.3%) when compared to non-fungal cases (17%, p = 0.046). Among Candida patients, mortality was similar in patients who received combination surgical and antifungal therapy versus antifungal therapy alone (33.3% vs. 27.8%, p = 0.26). New antifungal drugs, particularly echinocandins, were used frequently. These multi-center data suggest distinct epidemiologic features of Candida IE when compared to non-fungal cases. Indications for surgical intervention are different and mortality is increased. Newer antifungal treatment options are increasingly used. Large, multi-center studies are needed to help better define Candida IE.

Enoxaparin as bridging anticoagulant treatment in cardiac surgery.

OBJECTIVE: To assess enoxaparin as bridging anticoagulant treatment in cardiac surgery. METHODS: Prospective registry of those patients who underwent cardiac surgery in our centre between December 2003 and June 2004 and required long-term anticoagulation. Subcutaneous enoxaparin was used as bridging anticoagulant treatment according to a pre-established protocol. The global thromboembolic risk was carefully assessed in all patients. All patients were followed up for 3 months. RESULTS: Of 140 patients who were included (mean (SD) age 66 (11); 49% female), 51 were already receiving long-term acenocumarol treatment before the index intervention. 50% of the patients were at high or very high risk for thromboembolic events in the postoperative period. The mean (SD) number of days between surgery and the first dose of anticoagulant was 2.01 (7) for acenocumarol and 1 (1.01) for enoxaparin. The mean (SD) daily dose of enoxaparin was 1.1 (0.27) mg/kg. Six thromboembolic events (4.3%; 95% CI 1.6 to 9.1) occurred, but only four of them were plausibly related to enoxaparin (2.9%; 95% CI 0.8 to 7.1). Six major haemorrhagic events (4.3%; 95% CI 1.6 to 9.1) occurred, but only three were plausibly related to enoxaparin (2.1%; 95% CI 0.4 to 6.1). CONCLUSIONS: These findings show a reasonable rate of adverse events using enoxaparin as bridging anticoagulant treatment in cardiac surgery. Randomised studies are necessary to evaluate the real efficacy and safety of enoxaparin as bridging anticoagulant treatment in cardiac surgery.

Infective endocarditis in Europe: lessons from the Euro heart survey.

OBJECTIVES: To describe the characteristics, treatment, and outcomes of active infective endocarditis (IE) in Europe. DESIGN: Prospective survey of medical practices in Europe. SETTING: 92 centres from 25 countries. PATIENTS: The EHS (Euro heart survey) on valvar heart disease (VHD) enrolled 5001 adult patients between April and July 2001. Of those, 159 had active IE. RESULTS: 118 patients (74%) had native IE and 41 (26%) had prosthetic IE. Mean (SD) age was 57 (16) years. Blood cultures were obtained for 113 patients (71%) before antibiotic treatment was started. Surgery was performed in 52% of patients. Reasons for surgery were heart failure in 60%, persistent sepsis in 40%, vegetation size in 48%, or embolism in 18%. Surgery was for implantation of mechanical prosthesis in 63%, bioprosthesis in 21%, aortic homograft in 5%, and valve repair in 11%. In-hospital mortality was 12.6%, being 10.4% in the medical group and 15.6% in the surgical group. Among the total population of 5001 patients, only 50% of those with native VHD had been educated on endocarditis prophylaxis and only 33% regularly attended dental follow up. Of patients with IE who had had a procedure at risk during the preceding year only 50% had received adequate prophylaxis. CONCLUSIONS: The EHS on VHD shows that patients with active IE have a high risk profile and often undergo surgery. However, there are deficiencies in obtaining blood cultures and applying prophylaxis. Mortality remains high, which is a justification for the improvement of patient management through education and the implementation of guidelines.

Experience with enoxaparin in patients with mechanical heart valves who must withhold acenocumarol.

OBJECTIVES: To evaluate the incidence of thromboembolic and haemorrhagic events in a cohort of patients with mechanical heart valves who had to withhold acenocumarol and were treated with enoxaparin. DESIGN: Observational prospective study. SETTING: In hospital; after discharge, and follow up by telephone call. PATIENTS AND METHODS: All consecutive patients with mechanical heart valves admitted to the authors' hospital between May 1999 and January 2002 who had to interrupt treatment with acenocumarol and were treated with enoxaparin as an alternative to other methods were enrolled. In each patient, the following characteristics were prospectively determined: the reason for interrupting acenocumarol, demographic data, estimated global risk for thromboembolic events, international normalised ratio before starting enoxaparin treatment, number of days taking enoxaparin, and mean level of anti-Xa activity during treatment. All patients were followed up through clinical history during the hospitalisation and by telephone after discharge to detect thromboembolic events. MAIN OUTCOME MEASURE: Presence of thromboembolic or haemorrhagic events. RESULTS: 82 patients were identified and followed up for a mean of 2.8 months (range 1.5-3.5 months) after discharge. 61 of them (74%) had one or more associated thromboembolic risk factors. Acenocumarol was interrupted (to perform an invasive procedure in 74 patients and because of haemorrhagic complication in 8) an average of 11.2 days (range 3-40 days). Most patients received the standard enoxaparin dose (1 mg/kg at 12 hour intervals). Mean (SD) anti-Xa activity was 0.58 (0.3) IU/ml (median 0.51). There were 8 minor and 1 major bleeding events during enoxaparin treatment. No thromboembolic complications were clinically detected during hospitalisation or during follow up (95% confidence interval 0% to 3.6%). CONCLUSIONS: Enoxaparin may be an effective and relatively safe substitute anticoagulant for patients with mechanical heart valves who must withhold acenocumarol.

[New aspects in aortic valve disease]. / Nuevos aspectos de la valvulopatía aórtica.

Renewed interest for aortic valve disease has evolved in recent years. Aortic valve replacement has become the second most frequent cause of cardiac surgery, following coronary bypass surgery. In addition, the etiologic and physiopathologic knowledge of this disorder has improved. In the present paper we analyze three aspects of the disease which are, at present, the subject of study and controversy: first, we discuss the possible relationship between degenerative aortic stenosis and atherosclerosis; second, the involvement of the aortic root in cases of bicuspid aortic valve; and third, the surgical indications in asymptomatic patients with either aortic stenosis or regurgitation.

[Practice guidelines of the Spanish Society of Cardiology on endocarditis]. / Guías de práctica clínica de la Sociedad Española de Cardiología en endocarditis.

Infectious endocarditis is a disease which mainly involves the cardiac valves. It has a bad prognosis and is caused by a great variety of microorganisms. Prophylaxis is important although the effectiveness and the best way to achieve it remain unclear. Recommendations are herein presented. The diagnosis is based on clinical, bacteriological, and echocardiographic findings mainly based on Duke's criteria. Transthoracic and transesophageal echography are not only of diagnostic value but are also a tool to determine the therapy to follow. Antibiotic therapy should be selected according to the organisms isolated and their in vitro susceptibility. Guidelines for empirical antibiotic therapy in cases of negative cultures are also included. Lastly, indications and time for surgery are discussed.

Strategy for optimal aortic regurgitation quantification by Doppler echocardiography: agreement among different methods.

BACKGROUND: Although different Doppler methods have been validated for aortic regurgitation quantification, the benefit of combining information from different methods has not been defined. METHODS: Our study included 2 phases. In the initial phase (60 patients), Doppler parameters (jet width, short-axis jet area, apical jet area, regurgitant fraction from pulmonary and mitral flow, and deceleration slope) were correlated with angiography; range values for each severity grade were defined and intraobserver and interobserver and intermachine variability were studied. In the validation phase (158 patients), defined value ranges were prospectively tested and a strategy based on considering as the definitive severity grade that in which the two best methods agreed was tested. RESULTS: Jet width had the best correlation with angiography (r = 0.91), and its ratio with the left ventricular outflow diameter did not improve the correlation (r = 0.85) and decreased reproducibility. Apical jet area and regurgitant fraction from pulmonary flow permitted acceptable quantification (r = 0.87 and 0.86, respectively) but with worse reproducibility. The other methods were not assessable in 20% to 30% of studies. Concordance with angiography decreased in jet width when the jet was eccentric (90% vs 77%, P <.01), in apical jet area when mitral valve disease was present (84% vs 65%, P <.02), and in short-axis jet area and regurgitant fraction from pulmonary flow with concomitant aortic stenosis (77% vs 44%, P <.002 and 77% vs 53%, P <.02, respectively). Agreement with angiography was very high (94 [95%] of 99) when severity grade coincided in both jet width and apical jet area. In 59 cases without concordance, regurgitant fraction from pulmonary flow was used as a third method. Overall, this strategy permitted concordance with angiography in 146 patients (92%). CONCLUSIONS: Jet width is the best predictor in aortic regurgitation quantification by Doppler echocardiography. However, better results were obtained when a strategy based on concordance between jet width and another Doppler method was established, particularly when the jet was eccentric.

Infective endocarditis due to Staphylococcus aureus: deleterious effect of anticoagulant therapy.

BACKGROUND: The use of anticoagulant therapy in patients with infective endocarditis (IE) is a controversial issue. OBJECTIVE: To study the impact of anticoagulant therapy on the clinical outcome, mortality, and cause of death in a series of patients with native and prosthetic left-sided Staphylococcus aureus IE. METHODS: This report is based on all consecutive cases of IE diagnosed at our hospital between 1975 to 1997. Clinical data, including the use of anticoagulant therapy at the time of diagnosis, were prospectively obtained, and antibiotic treatment and surgical indications were uniform throughout the study period. Computed tomographic scans of all clinical records were reviewed. RESULTS: Of 637 consecutive patients with IE, 56 had left-sided S aureus IE affecting native valves in 35 patients and prosthetic valves in 21 patients. Of the patients with prosthetic valve IE, 19 (90%) were taking oral anticoagulant therapy at the time of diagnosis while no patient with native valve IE was receiving such treatment. There were no differences between native valve IE and prosthetic valve IE in age, sex, embolic episodes, and number of central nervous system complications. Mortality was higher in prosthetic valve IE than in native valve IE (71% vs 37%; P=.02). No patient with native valve IE died due to central nervous system complications, while 73% (11 of 15 patients) with prosthetic valve IE died due to central nervous system complications. The difference in the distribution of the type of death (stroke vs other) was significant (P<.007). CONCLUSIONS: Our results suggest that in left-sided S aureus IE anticoagulant therapy is closely associated with death due to neurologic damage. According to our data, as soon as the clinical diagnosis of S aureus IE is indicated the use of anticoagulant therapy should be immediately stopped until the septic phase of the disease is overcome.

Clinical outcome and long-term prognosis of late prosthetic valve endocarditis: a 20-year experience.

A prospective study of the clinical characteristics and evolutionary patterns of 59 cases of late prosthetic valve endocarditis (LPVE) that occurred between January 1975 and December 1994 was performed. Of these 59 cases of LPVE, 48 involved mechanical valves and 11 involved biological valves. Etiologies were as follows: streptococci, 41% of cases; staphylococci, 25%; enterococci, 13%; and miscellaneous, 21%. Echocardiography documented vegetations in 21 patients, paravalvular abscesses in 10, and prosthetic leaks in 34. Emboli occurred in 22 patients, and heart failure in 19 patients. Forty-two patients received medical treatment alone, and 17 received medical treatment and underwent valve replacement surgery. The in-hospital mortality rate was 25%; staphylococcal infection caused 67% of deaths, streptococcal infection caused 5%, and other etiologies caused 23% (P = .0004). After adjustment for age and type of prosthesis, multiple logistic regression revealed an odds ratio for death due to nonstreptococcal infections of 9.67. The overall survival rate was 59% at 5 years and 52% at 10 years. During follow-up, 17 patients needed new valves. At the end of follow-up, only 13 patients remained alive and had the same prosthesis that they had at the time of the diagnosis of LPVE.

Previous aspirin use may attenuate the severity of the manifestation of acute ischemic syndromes.

BACKGROUND: The present study was designed to investigate whether the prior use of aspirin could influence the severity of the manifestation of acute coronary artery syndromes, given the well-documented observations that aspirin can prevent myocardial infarction, stroke, and death in cardiovascular disease. METHODS AND RESULTS: A series of 539 consecutive patients admitted to the Coronary Care Unit of a General Hospital was carefully characterized in a study with an ambidirectional design, with regard to previous medical history, aspirin use, and subsequent hospital diagnosis. Among the 214 patients previously taking aspirin, the hospital diagnosis was myocardial infarction in 24% and unstable angina in 76% compared with 54% and 46%, respectively, among the 325 not taking aspirin (P < .0001), for a reduction in the odds ratio of myocardial infarction with aspirin of 72% (95% CI, 59% to 90%). The decrease in odds was homogeneous in all subsets studied and independent of age, sex, previous angina, or previous myocardial infarction. The myocardial infarction was of a Q-wave type in 62% of aspirin users compared with 76% of nonusers (P < .05). By multivariate analysis, previous aspirin use was a strong predictor of unstable angina versus myocardial infarction and the only independent predictor of non-Q-wave versus Q-wave myocardial infarction. CONCLUSIONS: This study, thus, suggests a shift to less severe manifestation of acute coronary syndromes with aspirin use, implying that the failure of the drug in many patients with an acute coronary syndrome is only partial and that aspirin has the potential of attenuating the severity of the underlying acute thrombotic disease process.