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Biomedical subjects

Ramón Corbalán

Publications and source records attributed to Ramón Corbalán.

At least 19 recordsLinked to original sources
PubMed2006

[Usefulness of thrombolytic therapy with low doses of streptokinase in acute myocardial infarction].

BACKGROUND: The optimal dose of Streptokinase in the treatment of acute myocardial infarction is not well established. Apparently, the thrombolytic efficacy would not increase with doses over 750,000 units. AIM: To compare the effectiveness and safety of treatment with low doses of Streptokinase, ranging from 500,000 to 750,000 units, in patients with ST elevation acute myocardial infarction. PATIENTS AND METHODS: From September 1993 to September 1998, the GEMI register of patients with acute myocardial infarction, was carried out in 37 hospitals, incorporating 4,938 patients. Of these, 1,631 patients received streptokinase. According to the administered dose of Streptokinase, patients were divided in two groups: 1,465 patients who received 1.5 millions U in 60 minutes (classical therapy group), and 166 patients with ischemic chest discomfort and either ST-segment elevation or left bundle-branch block on the electrocardiogram, who received 500,000 to 750,000 U streptokinase administered in no more than 30 minutes, with heparin, within 0 to 6 hours of symptom onset. Successful reperfusion, mortality, complications, and hospital outcome was evaluated in both groups. RESULTS: The low dose group of patients had a better reperfusion criteria profile. No differences between groups were observed in patient evolution, mortality, maximum Killip classification, post myocardial infarction heart failure, ischemic complications, arrhythmias or mechanical complications. CONCLUSIONS: These results suggest that streptokinase in low doses is at least as effective as classical therapy, in the treatment of ST elevation acute myocardial infarction.

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PubMed2005

[Prevalence of cardiovascular risk factors among patients suffering vascular events on admission and one year later].

BACKGROUND: International studies show a low compliance with norms for the management of cardiovascular risk factors. AIM: To assess the prevalence of risk factors in patients admitted for a coronary or vascular event and to evaluate the proportion of patients that normalize these factors after one year of follow up. MATERIAL AND METHODS: Three hundred and fifty seven patients aged 64+/-13 years (264 males), admitted to a University Clinical Hospital for a coronary or vascular event were studied. They were educated about cardiovascular risk factors and followed by their treating physicians for a mean of 11.9+/-2 months. During this period, smoking habits, body mass index. blood pressure, serum lipid levels, blood glucose and the appearance of new cardiovascular events were registered. RESULTS: One year survival was 96% (all 13 deaths were of cardiac origin). Eighty seven percent of patients were free of major cardiovascular events. At discharge from hospital and at the end of follow up 49% and 44% had a total cholesterol over 200 mg/dl respectively, 9,6% and 20,8% had systolic pressure over 140 mmHg. There was no diastolic hypertension in these patients, 27% and 31% had a body mass index over 25 kg/m2 and 2% smoked (versus 32% before the event). CONCLUSIONS: After one year of follow up, the prevalence of risk factors in patients that had suffered a cardiovascular event, continues to be high.

Cardiovascular Diseases↗
PubMed2005

C-reactive protein and atrial fibrillation: "evidence for the presence of inflammation in the perpetuation of the arrhythmia".

BACKGROUND: Atrial fibrillation (AF) is associated to a high risk of systemic embolism. The mechanisms that contribute to thrombogenesis in these patients are still poorly understood. Systemic and/or local inflammation could be involved in the process of thrombogenesis and contribute to the perpetuation of the arrhythmia. The purpose of the study was to evaluate the role of inflammation and its relation to thrombogenesis and cardiac rhythm in AF. METHODS: We prospectively studied 130 patients with newly diagnosed non-valvular AF in absence of antithrombotic therapy. Determinations of C-reactive protein (CRP) and thrombin-antithrombin complex (TAT) plasma levels, along with a transesophageal echocardiogram were performed in all the patients at admission. RESULTS: Mean age of the group was 67+/-14 years. CRP levels were significantly elevated in AF patients versus controls (matched by age, gender and cardiovascular risk factors) (1.0+/-1.8 versus 0.3+/-0.4 mg/dl, respectively, p<0.01). Baseline TAT levels were also significantly elevated in AF patients but no correlation was found between CRP and TAT. At 1-year of follow-up, mean CRP levels were still elevated in patients that remained in AF compared to those who converted to sinus rhythm (1.2+/-1.8 compared to 0.5+/-1.5 mg/dl, p=0.03). CRP was the only biochemical predictor of sinus rhythm maintenance at 1-year follow-up independently of clinical (including adjustment for risk factors and antiarrhythmic drugs), biochemical and echo parameters. CONCLUSIONS: There is evidence for the presence of inflammation in patients with non-valvular AF, which is not related to activation of the coagulation cascade. The persistence of inflammation is associated with chronic AF at 1-year follow up.

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PubMed2004

Association of diabetes mellitus and glycemic control strategies with clinical outcomes after acute coronary syndromes.

BACKGROUND: Diabetes is associated with an increased risk for coronary artery disease (CAD) and its complications. The relative effect of glucose-lowering strategies of "insulin provision" versus "insulin sensitization" among patients with CAD remains unclear. METHODS: To evaluate the associations of diabetes and hypoglycemic strategies with clinical outcomes after acute coronary syndromes, we analyzed data from 15,800 patients enrolled in the SYMPHONY and 2nd SYMPHONY trials. RESULTS: Compared with nondiabetic patients, patients with diabetes (n = 3101; 19.6%) were older, more often female, more often had prior CAD, hypertension, and hyperlipidemia, and less often were current smokers. The diabetic cohort had higher 90-day unadjusted risk of the composite of death/myocardial infarction (MI)/severe recurrent ischemia (SRI), death/MI, and death alone, as well as a near doubling of 1-year mortality rates. At 1 year, diabetes was associated with significantly higher adjusted risks of death/MI/SRI (OR, 1.3 [95% confidence interval, 1.1, 1.5]) and death/MI (OR, 1.2 [1.0, 1.4]). Hypoglycemic therapy including only insulin and/or sulfonylurea (insulin-providing; n = 1473) was associated with higher 90-day death/MI/SRI compared with therapy that included only biguanide and/or thiazolidinedione therapy (insulin-sensitizing; n = 100) (12.0% vs 5.0%); (adjusted OR, 2.1 [1.2, 3.7]). CONCLUSIONS: Diabetic patients with acute coronary syndromes had worse clinical outcomes. Although the findings regarding the influence of glycemic-control strategies should be interpreted with caution because of the exploratory nature of the analyses and the relatively small sample size of the insulin-sensitizing group, the improved risk-adjusted outcomes associated with insulin-sensitizing therapy underscore the need to further evaluate treatment strategies for patients with diabetes and CAD.

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PubMed2004

[Results of the first Chilean registry of unstable angina. Clinical features, risk profile and treatment].

BACKGROUND: From January 2000 to June 2002, the first Chilean registry of unstable angina was carried out, with the participation of 15 hospitals. AIM: To report the clinical and demographic features of 600 patients with unstable angina, their risk profile and prognosis. MATERIAL AND METHODS: The inclusion criteria for this prospective registry were a history of recent onset of chest pain (<48 hours) or a change in the character of previous angina, associated to ischemic electrocardiographic changes and/or positive markers of myocardial damage. RESULTS: Mean age of the patients was 65 years and 37% were women. Among coronary risk factors, 63% had hypertension, 27% had diabetes, 52% had dyslipidemia, 31% smoked and 21% had a family history of atherosclerosis. On admission 94% of patients had chest pain, associated to ST segment depression in 44%, negative T waves in 28% and positive markers of myocardial damage in 30%. Fifty seven percent received intravenous nitroglycerin, 47% received oral nitrates, 69% beta blockers and 15%, calcium antagonists. Antithrombotic therapy included aspirin in 96%, heparin in 74%, ticlodipine or clopidogrel in 19% and IIb/IIIa inhibitors in 12%. A coronary angiogram was performed in 52%, angioplasty in 25% and coronary bypass surgery in 13%. Hospital mortality was 2.6%. The incidence of new ischemic events was: myocardial infarction in 2.8% recurrent ischemia in 9.5% and refractory ischemia in 2%. The incidence of adverse events increased according to a higher risk profile. CONCLUSIONS: The demographic and clinical features, treatment and mortality of these patients are similar to those reported in international registries, with a low mortality rate.

Adult↗
PubMed2004

[Prognostic value of hyperuricemia in chronic heart failure].

BACKGROUND: Hyperuricemia has been proposed as a risk marker in chronic heart failure, but its value as an independent prognostic is not well established. AIM: To determine the prognostic value of hyperuricemia, in patients with chronic stable heart failure. PATIENTS AND METHODS: Forty six male patients with chronic heart failure, aged 62 +/- 13 years, were studied. Their election fraction was less than 40% and their serum creatinine was less than 2 mg/dl. Serum uric acid and catecholamines, maximal oxygen consumption (VO2 max) and left ventricular ejection fraction were measured. Mortality and the need for cardiac transplant were recorded as endpoints during a mean follow up of 39 +/- 18 months. The relationship between basal measures and the occurrence of events was analyzed using univariate and multivariate methods. RESULTS: Basal VO2 max and left ventricular ejection fraction were 16 +/- 4.6 ml/kg/min and 22 +/- 7% respectively. Eighteen patients died and three required transplantation during the follow up. Patients reaching these endpoints had a lower VO2 max and left ventricular ejection fraction and higher uric acid levels. Multivariate analysis accepted left ventricular ejection fraction (relative risk 0.89, 95% CI 0.82-0.97) and serum uric acid (relative risk 1.335 95% CI 1.02-1.74) as significant predictors of events. The relative risk for cardiac transplantation was 7.07 times higher among those with a serum uric acid over 7 mg/dl. CONCLUSIONS: A high serum uric acid is an independent predictor of bad prognosis in patients with stable chronic heart failure.

Analysis of Variance↗
PubMed2004

[Effects of carvedilol on functional capacity, left ventricular function, catecholamines and oxidative stress in patients with chronic heart failure].

INTRODUCTION AND OBJECTIVE: Carvedilol is an antioxidant and adrenergic antagonist with demonstrated benefits in terms of mortality from heart failure (HF). The aim of the present study was to evaluate clinical parameters, left ventricular function, oxidative stress levels and neurohumoral status at baseline and after 6 months of treatment with carvedilol in patients with chronic HF. PATIENTS AND METHOD: Thirty patients with chronic HF that was stable without beta blocker treatment were included. Functional class was II or III, and left ventricular ejection fraction (LVEF) was < 40%. Mahler score, distance walked in 6 min, peak oxygen consumption, LVEF, plasma catecholamine (norepinephrine) concentration and oxidative stress parameters were evaluated at baseline and after 6 months of treatment with carvedilol. RESULTS: Mean age was 59 (2) years, and 23 patients were men. After 6 months of treatment there were clinical improvements as measured by the Mahler score (from 6.8 to 11.0 points; P=.001) and the 6-min walk distance (from 499 [18] to 534 [17] m; P =.032), but no changes in peak oxygen consumption. The LVEF increased from 24 (1) to 31 (2)% (P=.003). In patients with chronic HF, plasma malondialdehyde concentration was significantly lower after 6 months (decrease from 2.4 [0.2] to 1.1 [0.2] micromol/l; P<.001). No significant changes were observed in plasma catecholamine levels or antioxidant enzyme activities. CONCLUSIONS: In patients with chronic HF, carvedilol treatment for 6 months was associated with clinical improvements, increased left ventricular function and decreased plasma concentrations of malondialdehyde, with no changes in plasma catecholamine levels.

Adrenergic beta-Antagonists↗
PubMed2003

Administration of growth hormone to patients with advanced cardiac heart failure: effects upon left ventricular function, exercise capacity, and neurohormonal status.

Experimental and clinical studies have shown that the administration of recombinant human growth hormone can improve deteriorated left ventricular function and hemodynamics in patients with heart failure. Herein, we compared the effects of growth hormone versus placebo upon resting left ventricular ejection fraction, exercise capacity and neurohormonal status in patients with advanced heart failure. Nineteen patients with advanced cardiac heart failure (ejection fraction <30%) were studied at baseline and after 8 weeks of treatment with growth hormone (0.03 U/kg per day) or placebo. Primary end points were resting left ventricular ejection fraction, peak oxygen consumption and neurohormonal status, including plasma norepinephrine levels and insulin like growth factor-1 and its binding protein-3. Results are presented as median and interquartile ranges. Patients receiving growth hormone had a significant increase in insulin growth factor-1 plasma levels (median difference growth hormone=83 ng/ml [57-170] versus placebo=-6 ng/ml [-23-6], P<0.05) and its binding protein-3. However, no significant increase in left ventricular ejection fraction after growth hormone treatment (ejection fraction pre=16% [13-18] and post=17% [14-27]) was noticed when compared to placebo (ejection fraction pre=20% [15-24] and post=20% [15-26]). Also, no significant effect of growth hormone treatment was seen on peak oxygen consumption or norepinephrine plasma levels. Although the administration of growth hormone to patients with advanced cardiac heart failure was associated with a significant increase in insulin growth factor-1, there were no significant changes in ejection fraction, exercise capacity and/or neurohormonal status.

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PubMed2003

Effects of glucose-insulin-potassium solution on myocardial salvage and left ventricular function after primary angioplasty.

OBJECTIVE: To evaluate the effects of glucose-insulin-potassium (GIK) therapy on infarct size and left ventricular function when used as an adjuvant therapy to primary angioplasty. DESIGN: Prospective, randomized, double-blind, placebo-controlled study. SETTING: Cardiac intensive care unit at a university hospital. PATIENTS: Thirty-seven patients with acute myocardial infarction for whom primary angioplasty was indicated. INTERVENTIONS: Eligible patients were randomized by a blinded pharmacist to GIK solution (30% glucose in water with insulin 50 U/L, and KCl 40 mM/L) vs. placebo at 1.5 mL/kg/hr for 24 hrs. MEASUREMENTS AND MAIN RESULTS: Tc 99m sestamibi myocardial scintigraphy was performed at admission and at 3 months. Primary end points were the changes in left ventricular ejection fraction (LVEF) and the size of salvaged myocardium. Baseline clinical characteristics were similar in both groups. At the 3-month follow-up, a significant overall decrease in infarct size (37 +/- 16% vs. 12 +/- 10%, p <.005) and an increase in LVEF (34 +/- 13% vs. 49 +/- 9%, p =.005) were observed. Patients randomized to GIK solution experienced a significant increase in their LVEF at 3 months (39 +/- 12 to 51 +/- 13, p =.002). Patients who received placebo had no significant differences between baseline and 3-month measurements (44 +/- 13 vs. 49 +/- 14, p = NS). There was a trend toward an increase in myocardial salvage in the GIK group, which did not reach statistical significance. When patients from both groups were compared directly, differences in LVEF improvement were no longer significant. CONCLUSIONS: GIK solution did not improve LVEF or decrease the infarct size among patients undergoing primary angioplasty.

Angioplasty, Balloon, Coronary↗
PubMed2002

[Coronary artery surgery in the first 24 hours after myocardial infarction].

BACKGROUND: Thrombolysis and angioplasty in the first hours after myocardial infarction minimize necrosis, leading to better early and late survival, but these therapies have limited effect in patients with three-vessel disease and cardiogenic shock. Emergency coronary surgery is an alternative treatment in some cases. AIM: To assess perioperative complications, mortality and long-term survival in patients undergoing coronary surgery within 24 h of myocardial infarction. PATIENTS AND METHODS: We retrospectively studied 57 patients undergoing surgery within 24 h of the onset of symptoms of myocardial infarction between 1982 and 1998. Multiple vessel disease was present in 31 patients (54%), shock or cardiac arrest in 19 (33%) and coronary angiography complications in 7 (12%). The mean time between onset of symptoms and surgery was 6.32 h. At the beginning of surgery 32 patients (56%) were hemodynamically stable, 15 (26%) were in shock and 10 (17%) were in cardiac arrest. RESULTS: The operative mortality was 0% for those who were hemodynamically stable at the start of surgery and 44% (11 of 25 patients) for those in shock or cardiac arrest. Shock or prior cardiac arrest were associated with higher rates of sternal infection and heart failure and longer hospital stays.Follow-up (mean 67 months) was possible for all remaining patients. The 5- and 10-year survival rates were 89 and 82%, respectively, for patients who were hemodynamically stable at the time of surgery. Five-year survival was 55%, however, for those who underwent surgery in shock or cardiac arrest. The overall rate of freedom from myocardial infarction, angioplasty or reoperation was over 95% at 5 years and over 85% at 10 years of follow-up. Age and shock or cardiac arrest were risk factors for a poor long-term outcome. CONCLUSION: The early and long-term outcome of coronary surgery within 24 h of myocardial infarction is good for patients who are hemodynamically stable when surgery begins. Shock and cardiac arrest are important risk factors for complication and death. Coronary artery bypass grafting is a good treatment option in the first hours after myocardial infarction.

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PubMed2002

[Persistence of oxidative stress after heart transplantation: a comparative study of patients with heart transplant versus chronic stable heart failure].

INTRODUCTION AND OBJECTIVE: Chronic heart failure (CHF) is associated with oxidative stress. Heart transplantation, an important therapeutic alternative in these patients, could reduce oxidative stress by improving cardiac function. Our aim was to evaluate post-heart transplantation oxidative stress. PATIENTS AND METHOD: We studied three experimental groups: a) heart transplant recipients without evidence of rejection (n = 11); b) NYHA class III CHF patients (n = 19), and c) healthy control subjects (n = 14). Oxidative stress was assessed by measuring plasma malondialdehyde levels (MDA), and determining the enzymatic activities of glutathione peroxidase (GSH-Px), catalase (CAT), and superoxide dismutase (SOD). RESULTS: The demographic characteristics of the three groups were similar. Mean time from transplantation was 20.0 4.8 months. Mean MDA plasma levels in heart transplantation and CHF patients were significantly higher than in normal subjects (3.35 0.8; 3.27 1.7 y 0.9 0.3 microM, respectively). GSH-Px activity increased after transplantation compared to control subjects (0.40 0.06 and 0.33 0.05 U/g Hb, respectively), but not the CHF group. A significant decrease in SOD activity was found in the heart transplant vs. CHF group (0.44 0.1 vs. 0.87 0.6 U/mg Hb). There were no differences in CAT values between heart transplant and CHF patients. CONCLUSION: These findings demonstrated the presence of permanent oxidative stress in patients who have undergone heart transplantation, characterized by an increase in MDA and a decrease in SOD activity, despite an increase in GSH-Px activity.

Adult↗
PubMed2002

Oxidative stress after reperfusion with primary coronary angioplasty: lack of effect of glucose-insulin-potassium infusion.

OBJECTIVE: To evaluate the oxidative stress status and the modification with glucose-insulin-potassium (GIK) therapy in patients with acute myocardial infarction undergoing primary percutaneous transluminal coronary angioplasty. DESIGN: Prospective, randomized, double-blinded, placebo-controlled study. SETTING: Cardiac intensive care unit at the university hospital. PATIENTS: Twenty patients were randomized to GIK solution (30% glucose in water with insulin 50 IU/L, and KCl 40 mM) vs. placebo (normal saline) at 1.5 mL/kg/hr for 24 hrs. The control group was 15 healthy volunteers with no heart disease. INTERVENTIONS: Eligible patients were randomized by a blinded pharmacist, patients with acute myocardial infarction were treated by primary percutaneous transluminal coronary angioplasty and randomized to GIK or placebo (saline solution). Primary angioplasty was successful in nine of ten patients (90%) and ten of ten patients (100%) in the GIK and placebo groups, respectively. Nine (100%) and six (60%) patients from GIK and placebo groups, respectively, underwent stent implantation. MEASUREMENTS AND MAIN RESULTS: We determined plasma levels of lipid peroxidation estimated by the malondialdehyde assay, superoxide dismutase, glutathione peroxidase, and catalase erythrocyte activities at admission and 0.5 and 24 hrs after angioplasty. Baseline determinations were compared with a control group (n = 15). Baseline clinical characteristics and time to treatment (4.5 +/- 3.5 hrs) were similar between groups. Angioplasty success rate (Thrombolysis in Myocardial Infarction [TIMI] 3 flow with residual stenosis < or = 30%) was 90% and 100% in GIK and placebo groups, respectively. Patients with acute myocardial infarction had an increase of malondialdehyde at baseline (2.9 +/- 1.7 vs. 1.1 +/- 0.3 microM, p <.01) and lower enzymatic activities of superoxide dismutase (0.5 +/- 0.5 vs. 1.3 +/- 0.4 U/mg hemoglobin, p <.01) and catalase (147 +/- 73 vs. 198 +/- 31 U/g hemoglobin, p <.01). These measurements did not change significantly after angioplasty and no differences were observed between GIK and placebo groups. CONCLUSION: Patients with acute myocardial infarction had increased levels of oxidative stress associated with a reduction in enzymatic antioxidant reserve. Administration of GIK solution did not improve these abnormalities among patients undergoing primary angioplasty.

Analysis of Variance↗
PubMed2002

[A 36 years experience with implantable pacemakers. A historical analysis].

BACKGROUND: The implantation of pacemakers improves cardiac function and quality of life, in particular with dual chamber DDD and DDDR modes. AIM: To evaluate our clinical experience and results on pacemaker implantation, from 1963 to 1998. MATERIAL AND METHODS: Computerized data collected from 2,445 consecutive paced patients was reviewed. A total of 3,554 operative procedures were performed, including 412 procedures for complications and 697 pacemaker replacement. Patient survival was determined from clinical records, inquiry to pacemaker manufacturers and death certificates from Servicio de Registro Civil e Identificación de Chile (Chilean Civil and Identification Registry). RESULTS: Use of dual chamber (DDD and DDDR) pacemakers increased progressively up to 74% from 1988 to 1998. Complication rate was 42% in the 1963-1976 study period, it decreased to 10.6% in the 1977-1987 study period, and to 5.6% by 1988-1998. Only two patients died during surgery in the study period (0.08%). In the 1977-1987 period, pacemakers lasted 10.6 years. Survival rates were 52% at ten years, 33% at 15 years, and 21% at 20 years, with a median survival of 11.7 years, and 7.24 years in patients over 80 years old. CONCLUSIONS: Transvenous permanent pacing can be accomplished today with a low complication rate, mainly due to better technology and surgical procedures.

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