Symmetrical compression distance for arrhythmia discrimination in cloud-based big-data services.

The current development of cloud computing is completely changing the paradigm of data knowledge extraction in huge databases. An example of this technology in the cardiac arrhythmia field is the SCOOP platform, a national-level scientific cloud-based big data service for implantable cardioverter defibrillators. In this scenario, we here propose a new methodology for automatic classification of intracardiac electrograms (EGMs) in a cloud computing system, designed for minimal signal preprocessing. A new compression-based similarity measure (CSM) is created for low computational burden, so-called weighted fast compression distance, which provides better performance when compared with other CSMs in the literature. Using simple machine learning techniques, a set of 6848 EGMs extracted from SCOOP platform were classified into seven cardiac arrhythmia classes and one noise class, reaching near to 90% accuracy when previous patient arrhythmia information was available and 63% otherwise, hence overcoming in all cases the classification provided by the majority class. Results show that this methodology can be used as a high-quality service of cloud computing, providing support to physicians for improving the knowledge on patient diagnosis.

Nonparametric signal processing validation in T-wave alternans detection and estimation.

Although a number of methods have been proposed for T-Wave Alternans (TWA) detection and estimation, their performance strongly depends on their signal processing stages and on their free parameters tuning. The dependence of the system quality with respect to the main signal processing stages in TWA algorithms has not yet been studied. This study seeks to optimize the final performance of the system by successive comparisons of pairs of TWA analysis systems, with one single processing difference between them. For this purpose, a set of decision statistics are proposed to evaluate the performance, and a nonparametric hypothesis test (from Bootstrap resampling) is used to make systematic decisions. Both the temporal method (TM) and the spectral method (SM) are analyzed in this study. The experiments were carried out in two datasets: first, in semisynthetic signals with artificial alternant waves and added noise; second, in two public Holter databases with different documented risk of sudden cardiac death. For semisynthetic signals (SNR = 15 dB), after the optimization procedure, a reduction of 34.0% (TM) and 5.2% (SM) of the power of TWA amplitude estimation errors was achieved, and the power of error probability was reduced by 74.7% (SM). For Holter databases, appropriate tuning of several processing blocks, led to a larger intergroup separation between the two populations for TWA amplitude estimation. Our proposal can be used as a systematic procedure for signal processing block optimization in TWA algorithmic implementations.

A study of the SCN5A gene in a cohort of 76 patients with Brugada syndrome.

We aim to study the SCN5A gene in a cohort of Brugada syndrome (BS) patients and evaluate the genotype-phenotype correlation. BS is caused by mutations in up to 10 different genes, SCN5A being the most frequently involved. Large genomic rearrangements in SCN5A have been associated with conduction disease, but its prevalence in BS is unknown. Seventy-six non-related patients with BS were studied. Clinical characteristics and family risk profile were recorded. Direct sequencing and multiplex ligation-dependent probe amplification (MLPA) of the SCN5A gene for identification of mutations and larger rearrangements were performed, respectively. Eight patients (10.5%) had point mutations (R27H, E901K, G1743R (detected in three families), V728I, N1443S and E1152X). Patients with mutations had a trend toward a higher proportion of spontaneous type I Brugada electrocardiogram (ECG) (87.5% vs 52.9%, p = 0.06) and had evidence of familial disease (62.5%, vs 23.5%, p = 0.03). The symptoms and risk profile of the carriers were not different from wild-type probands. There were non-significant differences in the prevalence of type I ECG, syncope and history of arrhythmia in carriers of selected polymorphisms. None of the patients had any deletion/duplication in the SCN5A gene. In conclusion, 10.5% of our patients had mutations in the SCN5A gene. Patients with mutations seemed to have more spontaneous type I ECG, but no differences in syncope or arrhythmic events compared with patients without mutations. Larger studies are needed to evaluate the role of polymorphisms in the SCN5A in the expression of the phenotype and prognosis. Large rearrangements were not identified in the SCN5A gene using the MLPA technique.

Acute disabling low-back pain during intravenous administration of amiodarone: could intravenous to oral switch therapy be a safe strategy?

We report for the first time a case of an acute disabling low-back pain episode during intravenous administration of amiodarone in a patient with atrial fibrillation. The symptoms completely resolved after terminating the infusion, and switching amiodarone from intravenous to oral administration was well tolerated.

A new algorithm for rhythm discrimination in cardioverter defibrillators based on the initial voltage changes of the ventricular electrogram.

AIMS: Ventricular activation onset is faster in supraventricular beats than in ventricular rhythms. The aim of this study was to evaluate a criterion to differentiate supraventricular (SVT) from ventricular tachycardia (VT) based on the analysis of the initial voltage changes in ICD-stored morphology electrograms. METHODS: Far field ICD-stored EGMs were obtained from 68 VT and 38 SVT episodes in 16 patients. The first EGM peak was detected, three consecutive time epochs were defined within the preceding 80 ms window and the voltage changes with respect to a sinus template were analysed during each time period and combined into a single parameter for rhythm discrimination. RESULTS: The algorithm was tested in an independent validation group of 442 VT and 97 SVT spontaneous episodes obtained from 22 patients with a dual chamber ICD. The area under the receiver-operator characteristics (ROC) curve indicated that the arrhythmia separability with this method was 0.95 (tolerance interval: 0.85-0.99) and 0.98 (0.87-0.99) for the control and validation groups respectively. A specificity of 0.91 was obtained at 95% sensitivity in the validation group. CONCLUSION: The analysis of voltage changes during the initial ventricular activation process is feasible using the far field stored electrograms of an ICD system and yields a high sensitivity and specificity for arrhythmia discrimination.

[Transient atrial fibrillation induced by adenosine in a patient with atrial tachycardia]. / Fibrilación auricular transitoria inducida por adenosina en una paciente con taquicardia auricular.

The administration of adenosine during atrial tachycardia usually terminates the arrhythmia or induces AV block and makes the diagnosis clear. We present a patient with atrial tachycardia in which the administration of adenosine induced a transient atrial fibrillation (AF). A continuous transition between both arrhythmias was observed and the original tachycardia persisted after the termination of the AF. This proarrhythmic effect may be due to the adenosine-mediated shortening of the atrial refractory periods, which produces a decreased wavelength of the reentry circuits and the potential coexistence of several wave-fronts in the atria, favoring the development of AF. The recognition of this uncommon effect is important, since the repeated administration of increasing doses of adenosine may induce sustained AF.

Fibrilación auricular transitoria inducida por adenosina en una paciente con taquicardia auricular / Adenosine-induced transient atrial fibrillation in a patient with atrial tachycardia

La administración de adenosina durante taquicardia auricular suele producir la terminación de la misma o aumentar el grado de bloqueo AV facilitando su diagnóstico. Presentamos un caso de inducción de fibrilación auricular (FA) transitoria por adenosina en una paciente con taquicardia auricular. La transición entre ambos ritmos fue contínua, persistiendo la taquicardia original al finalizar la FA. Este efecto proarrítmico se cree debido al acortamiento de los peridodos refractarios auriculares inducido por la adenosina, disminuyendo la longitud de onda de los circuitos de reentrada y facilitando de este modo la coexistencia simultánea de varios frentes de activación en las aurículas como ocurre en la FA.Aunque es un fenómeno poco común, su reconocimiento es importante para evitar la administración repetida de dosis crecientes de adenosina, que podría llevar a la inducción de FA sostenida (AU)

[Prognostic significance of the implantation of a temporary pacemaker in patients with acute myocardial infarction]. / Significado pronóstico de la implantación de marcapasos transitorio en pacientes con infarto agudo de miocardio.

OBJECTIVE: Indication of temporary pacemakers in patients during acute myocardial infarction was widely studied in the pre-thrombolytic era without having determined whether the generalization of fibrinolysis might have changed the overall incidence and significance of temporary pacemakers. Our aim was to determine the incidence and the prognostic significance of insertion of temporary pacemakers in patients with acute myocardial infarction. PATIENTS AND METHODS: In a study involving 1,239 patients consecutively admitted to hospital with acute myocardial infarction we studied clinical characteristics and prognosis depending on temporary pacemaker insertion or not. We performed an univariate analysis on in-hospital mortality and those selected variables were introduced in to a logistic regression analysis. RESULTS: A temporary pacemaker was indicated in 55 patients (4.4%), prophylactically in 22% and therapeutically in 78%. Temporary pacemakers were inserted in 55% of the patients with advanced AV block and in the 10% of the patients with bundle-branch block. Pacemaker insertion was associated with higher number of affected leads in the ECG, and higher CK peak, regardless of the association with thrombolysis. The following complications were more often observed in patients with temporary pacemakers: atrial fibrillation, heart failure, right bundle-branch block, advanced atrioventricular block and in-hospital mortality (45.4 vs 10.2%; p < 0.001). Need for a temporary pacemaker was less frequent in patients treated with thrombolytics compared with those not treated (3.0 vs 6.1%; p < 0.02). Pacemaker insertion had an independent value for predicting in-hospital mortality (OR = 5.51; 95% CI, 2.71-11.19). CONCLUSION: The insertion of a temporary pacemaker in acute myocardial infarction is less frequent nowadays than on the pre-thrombolytic era. Pacemaker insertion is associated with higher indices of infarct extension and in-hospital mortality, having independent prognostic value on the in-hospital mortality.

[Concurrent long QT and Brugada syndrome in a single patient]. / Presentación de síndrome de Brugada e intervalo QT largo en un mismo paciente.

We present a 61-year-old patient with previous cardiac arrest and frequent syncopal spells. ECG showed a typical Brugada pattern and a QTc interval of 425 ms. During programmed ventricular stimulation a self-limited syncopal polymorphic ventricular tachycardia was induced. On diagnosis of the Brugada syndrome an implantable cardioverter defibrillator was implanted. Two days later two episodes of polimorphic ventricular arrhythmia were converted by the device. The ECG at this time showed a prolonged QTc of 500 ms in addition to a typical Brugada pattern. Atenolol was started and after a 36-month follow-up the patient has remained asymptomatic without arrhythmic events. In conclusion, this patient has the Brugada syndrome and also fulfills the clinical and ECG characteristics of the Long QT syndrome. These findings suggest a genetic link between the two syndromes.

Comparative study of treatment with penicillin, ceftriaxone, trovafloxacin, quinupristin-dalfopristin and vancomycin in experimental endocarditis due to penicillin- and ceftriaxone-resistant Streptococcus pneumoniae.

The efficacy of different antibiotics was compared in an experimental model of aortic valve endocarditis in rabbits, using a serotype 19 strain of Streptococcus pneumoniae resistant to penicillin (MIC 12 mg/L) and ceftriaxone (MIC 12 mg/L). The results were compared with those of a control group, which received no treatment. One hundred and nineteen animals were treated with one of the following antibiotic regimens: im procaine penicillin G at a dosage of 300,000 U/kg weight/12 h (16 animals); iv trovafloxacin, 13.3 mg/kg/12 h (31 animals); iv ceftriaxone, 75 mg/kg/24 h (21 animals); iv vancomycin, 20 mg/kg/12 h (15 animals) and im quinupristin-dalfopristin, 30 mg/kg/8 h (20 animals). All the antibiotics used in this study proved to be efficient in reducing numbers of S. pneumoniae and in increasing the percentage of aortic vegetations that were rendered sterile compared with the control group. Penicillin at the dosage used in our study was capable of achieving serum concentrations two or three times greater than the MIC, thus demonstrating its effectiveness as an antibiotic for this endocarditis model. No significant difference was observed between the effects of vancomycin, quinupristin-dalfopristin and penicillin. Vancomycin proved to be more efficient than trovofloxacin in reducing the bacterial load and increasing the numbers sterilized. There was also a tendency for this antibiotic to be more effective than ceftriaxone in reducing the bacterial load of the vegetations. There was a statistically significant correlation between the weight of the vegetations and their bacterial load. In the light of these results, vancomycin and quinupristin-dalfopristin may be considered suitable alternatives to penicillin for the treatment of penicillin-resistant S. pneumoniae endocarditis.

Prognostic significance of bundle-branch block in acute myocardial infarction: the importance of location and time of appearance.

BACKGROUND: The presence of bundle-branch block (BBB) is associated with high mortality rates and is considered an important predictor of poor outcome in patients with acute myocardial infarction (AMI). HYPOTHESIS: The objective of this study was to assess the prognostic significance of BBB in patients with AMI depending on its form of presentation. METHODS: A multicenter prospective 1-year follow-up study involving 1,239 consecutive patients diagnosed with AMI was performed. RESULTS: Bundle-branch block was present in 177 cases (14.2%), associated with worse clinical characteristics, lower rate of thrombolytic therapy, and higher mortality: in-hospital (23.8 vs. 9.7%, p < .01) and 1-year (40.9 vs. 16.9%, p < 0.01). Compared with right BBB (n = 135), left BBB (n = 42) was more often associated with female gender and higher prevalence of cardiovascular diseases, but had a similar 1-year mortality. In the absence of heart failure or complete atrioventricular (AV) block, there was no difference in in-hospital mortality of patients with BBB (n = 76) and without BBB (n = 786) (2.6 vs. 3.9%). Compared with existing BBB (n = 113), BBB of new appearance (n = 64) was more often accompanied by complete AV block and heart failure and higher in-hospital and 1-year mortality rates. Only BBB of new appearance was an independent predictor of mortality: in-hospital (odds ratio [OR] 2.3, 95% confidence interval [CI] 1.1-4.7) and 1-year mortality (OR 3.2, 95% CI, 1.7-9.1). CONCLUSIONS: In patients with AMI, the classification of BBB according not only to location but also to time of appearance is of practical interest. New BBB is an independent predictor of short- and long-term mortality.

[Impact of diabetes mellitus on the late clinical outcome of coronary revascularization with stents]. / Influencia de la diabetes mellitus en los resultados clínicos tardíos de la revascularización coronaria con stents.

INTRODUCTION: The Influence of diabetes mellitus in the late outcome of coronary stenting remains controversial. AIM: The aim of this study was to determine the late clinical outcome of diabetics in comparison with non diabetics and to establish whether there are subgroups of diabetic patients with a greater need for target lesion revascularization. METHODS: Two hundred sixteen consecutive patients (74 diabetics; 95 stents in 90 lesions and 142 non diabetics) who had successfully undergone coronary stenting were included in the study and followed over 17.6 +/- 10 months. The clinical events evaluated were target lesion revascularization, death and acute myocardial infarction. Independent predictive variables of target lesion revascularization were studied in both groups of patients. RESULTS: The diabetic patients presented greater cardiovascular mortality (6.7% vs 1.4%; p=0.02) but the incidence of infarction was similar in the two groups (2.7% vs. 3.5%; p=0.6). The accumulated rate of target lesion revascularization at two years was 18.2% in diabetics vs 13.3% in non diabetics (p=0.09), respectively. The presence of three vessel disease (p=0.014), history of arterial hypertension ([=0.011) and residual stenosis > 0% (p=0.005) were specific predictive factors of target lesion revascularization for diabetic patients and together with vessel diameter < 3mm (p<0.001) subgroups of diabetics were independently selected with a significantly greater incidence of target lesion revascularization than the non diabetic patients. CONCLUSIONS: Following coronary stenting, diabetic patients show a greater cardiovascular mortality than non diabetics, but only some subgroups of diabetics (small vessels extensive coronary disease, associated arterial hypertension, residual stenosis) show a significantly greater risk of target lesion revascularization.

[Subacute thrombosis with antiplatelet treatment in a non-selected population of intracoronary stents: incidence and predictors]. / Trombosis subaguda con tratamiento antiagregante en una población no seleccionada de stents intracoronarios: incidencia y predictores.

INTRODUCTION: After coronary stenting, the incidence of subacute stent thrombosis have been reduced to 0% using aspirin and ticlopidine, in studies with selected populations and intracoronary ultrasounds. OBJECTIVE: To evaluate the incidence and predictors of subacute stent thrombosis in a nonselected population, using antithrombotic therapy. METHODS: We studied 285 stents, consecutively and successfully implanted in 268 lesions of 226 patients. We used high pressure balloon inflation without intracoronary ultrasound. Post-stenting protocol included aspirin and ticlopidine during four weeks with no anticoagulation. We defined subacute stent thrombosis as death, acute myocardial infarction myocardial infarction or angiographic occlusion of stent, with TIMI flow 0-1, after the first 24 hours and during the first month. RESULTS: Four patients presented events (1.7%): Three nonfatal myocardial infarction after discharge, with documented angiographic thrombosis of stent, and one death due to in-hospital myocardial infarction. All three non-fatal AMI, occurred in vessels less than 3 mm (p = 0.07) and in patients taking aspirin without ticlopidine (p < 0.001). After discharge, three (17%) of 18 patients with inadvertent discontinuation of ticlopidine presented subacute stent thrombosis, in contrast to none of 25 patients taking ticlopidine without aspirin. Excluded patients with discontinuation of ticlopidine, the incidence of subacute stent thrombosis was 0.5%. CONCLUSION: After intracoronary stenting in a nonselected population, using antithrombotic treatment with aspirin and ticlopidine, we may expect a rate of subacute stent thrombosis about 1%. Ticlopidine seems to have the main role in preventing subacute stent thrombosis, above all in predisposing circumstances as small vessels.

[Intracoronary stents in small vessels: short- and long-term clinical results]. / Stents intracoronarios en vasos pequeños: resultados clínicos a corto y largo plazo.

OBJECTIVE: To assess the clinical outcome of coronary stenting in small vessels (< 3 mm), using high pressure balloon inflation and antithrombotic therapy. PATIENTS AND METHODS: Vessel size was evaluated as < or >= 3 mm at the time of procedure and measured at a level of maximum diameter. We studied 234 consecutive patients with placement of 300 stents in 279 lesions, comprising 84 stents implanted in 79 lesions located at small vessels (< 3 mm). The standard technique included high pressure balloon inflation (15.8 +/- 2.2 atm) and post-stenting therapy with ticlopidine and aspirin for one month. Mean clinical follow-up was 17.6 +/- 10 months. RESULTS: Procedural success without in-hospital major events was similar between small and large vessels (93.7 in vessels of < 3 mm vs 93.5% in vessels of >= 3 mm; p = NS). Three small vessels presented subacute stent thrombosis, whereas no thrombotic occlusion occurred in large vessels (3.8 vs 0%; p = 0.006). At two years, small vessels had a lower target lesion revascularization free survival (73.6 vs 90.3%; p < 0.001). After adjustment for variables previously described as predictors of stent restenosis, in multivariate analysis, a small vessel of < 3 mm was an independent predictor of target lesion revascularization (p = 0.001). Although patients with stenting in small vessels did not differ significantly in terms of any cause death (4.6 vs 3.8%; p = 0.7) nor acute myocardial infarction (2.9 vs 1.1%; p = 0.3), event-free survival was significantly lower after two years (69.1 vs 86.6%; p < 0.001). CONCLUSIONS: As compared to large vessels, coronary stenting in small vessels was performed with similar rates of initial success, however they had a significantly worse clinical long-term outcome in terms of subacute stent thrombosis and target lesion revascularization at follow-up.

Spontaneous sustained monomorphic ventricular tachycardia after administration of ajmaline in a patient with Brugada syndrome.

We present the case of a 13-year-old boy with an episode of aborted sudden death, absence of structural heart disease, and a characteristic ECG pattern of right bundle branch block with persistent ST-segment elevation in the right precordial leads, in whom a monomorphic sustained ventricular tachycardia developed spontaneously after the administration of ajmaline. This effect may be related to an increased inhomogeneity of repolarization mediated by the drug and demonstrates the arrhythmogenic potential of Class I antiarrhythmic drugs in patients with Brugada syndrome.

[Prognostic significance of advanced atrioventricular block in patients with acute myocardial infarction]. / Significación pronóstica del bloqueo auriculoventricular avanzado en pacientes con infarto agudo de miocardio.

BACKGROUND: Advanced atrioventricular block (AB) during acute myocardial infarction (AMI), characterizes a high-risk subgroup of patients. Our aim was to determine the prognostic significance of AB and its possible peculiarities in relation to infarction localization and/or the thrombolytic therapy. PATIENTS AND METHODS: The prospective study involved 1,239 patients with AMI. We studied clinical characteristics, as well as indexes of infarct size, short and long-term complications. RESULTS: AB was present in 85 (6.8%) patients and was more often associated with: previous treatment with diuretics, diabetes, inferior localisation, higher number of ECG leads with elevated ST segment, and higher peak of CK. The AB was associated with a higher mortality: in-hospital (27% vs 10.6%; p < 0.01)) and after one-year (31.7% vs 19.4%; p < 0.05). Patients with AB had a different in-hospital mortality depending on anterior or inferior infarct localization (66% vs 18.5%; p < 0.001, respectively). In patients receiving thrombolytic treatment (n = 681), the duration of AB was shorter and in-hospital mortality was lower (13.7% vs 47%, p < 0.11) than that occurred in patients without this treatment (n = 558). AB had independent value for predicting in-hospital mortality (OR: 3.56; 95% CI: 1.84-6.90) and one-year mortality (OR: 2.77; 95% CI: 1.52-5.04). CONCLUSIONS: AB is associated with larger infarcts and higher incidence of complications. The prognosis is especially poor when it is presented associated with anterior infarction and/or in patients without thrombolytic treatment. AB is a variable with independent prognostic value on the mortality.

[The long-term clinical results of the implanting of intracoronary stents in current practice]. / Resultados clínicos a largo plazo del implante de stents intracoronarios en la práctica actual.

INTRODUCTION: Published Stress and Benestent studies, obtained in selected populations under technical conditions that do not reflect present practice with intercoronary stenting showed a clinical benefit of coronary stenting. OBJECTIVE: To assess clinical longterm outcome of coronary stenting in current practice and to compare coronary lesions with and without Stress/Benestent criteria. METHODS: 216 consecutive patients with successful placement of 279 stents in 256 lesions and no major in-hospital events. Mean clinical follow-up was 16.7 +/- 10.4 months. Standard technique included seven types, high pressure balloon inflation (15.6 +/- 2.2 atm) and post-stenting treatment of four weeks with aspirin and ticlopidine. RESULTS: Cumulative rates of target lesion revascularization were 9.7% at 6 months, 13.5% at 12 months and 15.1% at 18, 24 and 36 months. Cumulative rates of combined clinical end-point (death, myocardial infarction and target lesion revascularization) were 11.3%, at 6 months, 13.9% at 1 year, 19.3% at 2 years and 21.1% at 3 years. No Stress/Benestent lesions were 193; 75%, and had a higher incidence of target lesion revascularization (17.9 vs 7.5%, Log Rank = 0.015) and combined clinical end-point (22.4 vs 10%, Log Rank = 0.025), than Stress/Benestent lesions. CONCLUSION: Coronary stenting of no Stress/Benestent lesions have a less favourable clinical longterm outcome. However, clinical outcome in a nonselected population at the present time is similar to the old Stress/Benestent studies, probably because of technical improvements.

[Incidence, clinical characteristics and prognostic significance of supraventricular tachyarrhythmias in acute myocardial infarction]. / Incidencia, características clínicas y significación pronóstica de las taquiarritmias supraventriculares en el infarto agudo de miocardio.

OBJECTIVES: The study of incidence and prognostic significance of supraventricular tachyarrhythmias in patients with acute myocardial infarction. PATIENTS AND METHODS: Prospective study on 1,239 patients consecutively admitted because of a diagnosis of acute myocardial infarction. Clinical characteristics, indexes of myocardial infarction and complications were analysed. RESULTS: Supraventricular tachyarrhythmias were observed in 116 (9.3%) cases: atrial fibrillation in 96 (7.7%); atrial tachycardia in 15 (1.2%); and atrial flutter in the remaining five cases (0.4%). Patients with supraventricular tachyarrhythmias were older, and presented higher heart rate, lower blood pressure, a higher number of affected leads in ECG, and higher Killip class. A higher creatine kinase peak and a lower left ventricular ejection fraction were associated with the presence of supraventricular tachyarrhythmias. Predictors of supraventricular tachyarrhythmias were: age, systolic blood pressure, number of affected leads in ECG, and congestive heart failure at admission. The following complications were found more frequently in patients with supraventricular tachyarrhythmias: bundle-branch block, complete A-V block, ventricular tachycardia, ventricular fibrillation; heart failure; stroke; and mortality, in-hospital 18.1% vs 11.1% (p < 0.05) and one-year, 38.7% vs 18.4% (p < 0.001). The logistic regression model showed that supraventricular tachyarrhythmias had no independent prognostic value on mortality. CONCLUSIONS: The appearance of supraventricular tachyarrhythmias during the acute phase of myocardial infarction is a relatively frequent finding, often associated with older age and larger infarctions. Supraventricular tachyarrhythmias are accompanied by higher short and long-term mortalities, although there is no independent prognostic significance.

Clinical and prognostic characteristics associated with age and gender in acute myocardial infarction: a multihospital perspective in the Murcia region of Spain.

Age and female gender have been associated with poor prognosis in acute myocardial infarction (AMI). Data currently available about the prognostic significance of gender in AMI might well have led to inappropriate/incomplete conclusions. A multicenter, prospective study on 1239 patients with AMI was conducted. Clinical characteristics, complications during the acute phase and one-year follow-up were monitored. Women constituted 24.1% of all patients. Female patients were older with more prevalence of diabetes, hypertension, and previous congestive heart failure. Compared with men, the following complications were more frequently found in women: heart failure, 43% vs. 22% (p < 0.001); reinfarction, 5% vs. 2% (p < 0.05); use of pacemaker, 7% vs. 4% (p < 0.05). Women had higher mortality: early, during the first 24 hours post-admission, 10.7 vs. 3.1%; in-hospital, 23% vs. 8.1%; and 1-year, 33.7% vs. 16% (p < 0.001 for all the 3 cases of mortality). In the age-groups considered (<65, 65-74, and > or =75 years), 1-year mortality increased exponentially with ageing in men: 7.8%, 21.3%, and 38.9%, whereas in women the figures were: 15.3%, 41.5%, and 38.8%. Multivariate analysis showed that, among other variables, age and female gender had independent prognostic value for in-hospital mortality whereas gender lost its prognostic significantly for 1-year mortality. Multivariate analysis restricted to those patients aged over 75 years showed that age but not gender had independent prognostic value. In conclusion, age and female sex have independent prognostic value for predicting mortality in patients with AMI. Mortality increases exponentially with ageing in men whereas it stabilises in the case of women over 65 years. Female gender loses its independent value for predicting mortality in patients over 75 years.