Biomedical subjects

Mariano Valdés-Chavarri

Publications and source records attributed to Mariano Valdés-Chavarri.

4 recordsLinked to original sources

PubMed2006

[Value of coronary blood flow pattern as a predictor of functional recovery and short-term left ventricular remodeling after primary coronary angioplasty. A transthoracic Doppler study].

INTRODUCTION AND OBJECTIVES: Coronary blood flow measurement using a Doppler guidewire is the most sensitive way of detecting the no-reflow phenomenon following reperfusion of a myocardial infarction (MI). New high-frequency Doppler probes enable coronary blood flow velocity to be measured noninvasively. Our aims were to study the different patterns of left anterior coronary artery blood flow observed by transthoracic Doppler echocardiography, and to describe their association with functional recovery following reperfusion of an anterior MI. METHODS: The study included 57 patients with a mean age of 60 years (range 30-85 years). An abnormal coronary blo:d flow pattern was defined as one in which there was a high peak diastolic velocity and a short deceleration time (i.e., < or = 500 ms). We compared the regional contractility, ventricular volumes, and left ventricular ejection fraction (LVEF) measured after 72 hours with those measured 1 month after MI. RESULTS: Overall, 31 patients (54%) had a normal coronary blood flow pattern (Group 1) and 26 (46%), an abnormal pattern (Group 2). After one month, regional contractility improved in Group-1 patients, as did LVEF, from 46.8 (8.6) to 52.6 (8.8)% (P=.002). In these patients, left ventricular volumes were unchanged. In contrast, regional contractility and LVEF remained unchanged in Group-2 patients whereas ventricular volumes increased, from 55.8 (12.9) to 62.9 (16.8) ml/m2 (P=.05), and from 32.2 (9.5) to 37.1 (14.9) ml/m2 (P< .05). Coronary blood flow pattern was the most important independent predictor of left ventricular remodeling, odds ratio =6.14 (95% CI, 1.56-24.17). CONCLUSIONS: Transthoracic Doppler echocardiographic assessment of coronary blood flow following reperfusion of an anterior myocardial infarction can be used to identify patients with microvascular damage who are progressing towards ventricular dilatation without recovery of myocardial function.

Adult↗

PubMed2006

[Prognostic role of new biomarkers in off-pump coronary artery bypass surgery].

The value of biomarkers of myocardial damage or inflammation in off-pump coronary artery bypass (OPCAB) surgery has not yet been established. In a prospective study of 51 consecutive patients scheduled for elective OPCAB surgery, preoperative levels of troponin T, C-reactive protein, interleukin-6 and tumor necrosis factor-alpha were determined. The primary endpoint was the combination of cardiac death or acute myocardial infarction (AMI) within 30 days. Seven patients (14%) presented with an adverse event: three cardiac deaths and six AMIs. Univariate analysis identified the following adverse event predictors: renal failure (50% vs 11%, P=.028), left ventricular ejection fraction 0.10 ng/dL (43% vs 9%, P=.016), and EuroSCORE rating (7.6 [2.5] VS. 5.2 [2.6], P=.031). A preoperative troponin-T level > 0.10 ng/dL (P=.03) was the only independent adverse event predictor. No significant differences were found with biomarkers of inflammation (P.05). The presence of a preoperative troponin-T level > 0.10 ng/dL is associated with a higher risk of cardiac death or AMI in patients undergoing OPCAB surgery.

Aged↗

PubMed2006

[In-hospital and long-term mortality in women with acute myocardial infarction treated by primary angioplasty].

INTRODUCTION AND OBJECTIVES: Mortality and morbidity after ST-elevation myocardial infarction (STEMI) are higher in women than men. It is not clear whether reperfusion by elective treatment with primary angioplasty can improve the poor prognosis in women with this condition. The objective of this study was to determine the effect of sex on clinical characteristics, and on in-hospital and long-term outcomes in patients with STEMI undergoing reperfusion by primary angioplasty. METHODS: A prospective observational study was performed in 838 consecutive patients with STEMI treated by primary angioplasty at a single hospital. Of these, 183 (22%) were women. RESULTS: Women were older (70 years vs 62 years; P<.01), were less frequently smokers (8% vs 53%; P<.01), more frequently had diabetes (45% vs 27%; P<.01) or hypertension (59% vs 36%; P<.01), presented later for angioplasty (4.1 h vs 3.6 h; P=.05), and experienced cardiogenic shock more frequently during the procedure (21% vs 12%; P<.01). There were no differences in the culprit vessel most often responsible for the infarction, in the procedural success rate, or in stent or glycoprotein IIb/IIIa inhibitor use. The total in-hospital mortality rate was higher in women (22% vs 9%; P<.01), as was the adjusted in-hospital rate (odds ratio 2.5, 95% confidence interval 1.2-5.2). During long-term follow-up after discharge (median 35.4 months), there was no significant difference in age-adjusted survival rate (relative risk 1.2, 95% confidence interval 0.7-1.9). CONCLUSIONS: Despite recent advances in the treatment of STEMI, women experience greater in-hospital mortality, even after adjustment for baseline clinical characteristics. However, the long-term age-adjusted mortality rate in women discharged from hospital was similar to that in men.

Aged↗

PubMed2002

Automatic discrimination between supraventricular and ventricular tachycardia using a multilayer perceptron in implantable cardioverter defibrillators.

The morphological analysis of implantable cardioverter defibrillator (ICD) stored electrograms (EGM) using a multilayer perceptron (MLP) has been proposed for discrimination between supraventricular and ventricular arrhythmias. However, a reliable estimation of the accuracy of MLP methods is lacking. The aim of the study was to compare the morphology and spectrum-based MLP with more conventional morphology-based algorithms in a large series of ICD-stored episodes of arrhythmia. One set of ICD-stored electrograms was used for control and training purposes and a second one, consisting of spontaneous episodes in patients with dual chamber ICDs, for validation of the MLP performance. The correlation waveform analysis (CWA) and the EGM width criterion were compared with MLP methods. Bootstrap resampling techniques were used to extract the relevant information in the MLP training. The morphology-based MLP achieved better discrimination than any other method, with areas under the receiver operating characteristic (ROC) curve (tolerance intervals): 0.96 (0.81, 0.96) for MLP, 0.91 (0.77, 0.94) for CWA, and 0.68 (0.49, 0.78) for EGM width in the validation set. A specificity of 73.0% was obtained at 95% sensitivity, compared with 38.1% and 55.1% using CWA and EGM width criteria, respectively. In contrast, the generalization capabilities of spectral-based MLP methods are poor, showing a lower area under the ROC curve in the validation set. Time-domain MLP techniques may be useful for the morphological analysis of the intracardiac EGM signal stored by ICD devices. When properly trained and validated, these methods perform better than other commonly used morphological criteria for discrimination between supraventricular and ventricular arrhythmias.

Algorithms↗