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Biomedical subjects

S Caponnetto

Publications and source records attributed to S Caponnetto.

At least 37 records · Page 2Linked to original sources

[Hyperinsulinemia and cardiovascular risk].

A large body of evidence has been accumulating that insulin plays a role in coronary heart disease (CHD). Hyperinsulinemia has been considered a risk factor for CHD according to prospective studies. Cross-sectional studies found an association between hyperinsulinemia and prevalence of CHD, while population studies have shown that populations at increased risk for CHD are hyperinsulinemic. Strong relations between hyperinsulinemia and atherosclerotic coronary lesions have been demonstrated by angiographic studies. It has recently been observed that also patients with microvascular angina are hyperinsulinemic. Several mechanisms have been proposed to explain the role of hyperinsulinemia in the development of atherothrombosis. Hyperinsulinemia is the consequence of insulin resistance, a defect in insulin-mediated glucose uptake. Experimental evidence suggests that insulin has actions that may promote atherosclerosis, which clinical studies suggest the existence of a metabolic syndrome characterized by the presence of major coronary risk factors in which insulin resistance is the common link.

Animals↗

[Heart involvement in thymic neoformations: the role of magnetic resonance tomography. Experience in 3 cases].

Three paracardiac masses (1 thymic cyst, 2 thymomas) were studied by magnetic resonance imaging (MRI) using spin-echo, multi-echo, and gradient-echo sequences (cine-MR). MRI showed: a pedunculate cystic lesion, typical for thymic origin, in Case 1; cardiac and pulmonary infiltration, and 3 intracardiac metastases, in Case 2; cardiovascular compression but not infiltration, in Case 3. In 3/3 cases MRI was superior to transthoracic echocardiography (TTE), and in 2/2 MRI was superior to computed tomography (CT), not performed in Case 2 (allergy to contrast agents). MRI may be considered the most important technique to evaluate cardiovascular involvement by thymic neoplasms. MRI should be performed after TTE and makes CT unnecessary.

Adult↗

Effectiveness and safety of a single intravenous bolus injection of tissue-type plasminogen activator in acute myocardial infarction. Bolus Dose-Escalation Study of Tissue-Type Plasminogen Activator (BEST) Investigators.

The efficacy of multiple intravenous bolus injections of tissue-type plasminogen activator (t-PA) in inducing rapid coronary recanalization in patients with acute myocardial infarction was previously demonstrated. In this Bolus Dose-Escalation Study of Tissue-Type Plasminogen Activator (BEST), the efficacy of 3 different doses of a single rapid intravenous bolus injection of t-PA (dute-plase, Wellcome Foundation, London) in inducing coronary patency (Thrombolysis In Myocardial Infarction perfusion grade 2 or 3) in 64 patients with acute myocardial infarction presenting less than 6 hours after onset of symptoms was investigated. At 60 minutes after administration of t-PA, the infarct-related coronary artery was patent in 9 of 17 patients (53%; 95% confidence interval [CI] 28 to 77%) after 0.3 MU/kg, in 14 of 23 (61%; 95% CI 39 to 80%) after 0.45 MU/kg and in 10 of 14 (71%; 95% CI 42 to 92%) after 0.6 MU/kg. At 90 minutes after t-PA, coronary patency was present in 9 of 17 cases (53%; 95% CI 28 to 77%) after 0.3 MU/kg, in 12 of 24 (50%; 95% CI 29 to 71%) after 0.45 MU/kg and in 10 of 13 (77%; 95% CI 46 to 95%) after 0.6 MU/kg. One patient in each dose group had a silent reoccluded infarct-related artery by 24 hours, and there were 2 clinical reinfarctions before discharge. No major bleeding events were observed. There were 5 hospital deaths, all unrelated to t-PA. A single intravenous bolus injection of 0.6 MU/kg of t-PA appears to be effective in inducing rapid coronary patency and to be safe in patients with acute myocardial infarction.

Adult↗

Gallopamil and diltiazem: a double-blind, randomized, cross-over trial in effort ischaemia.

The aim of this study was to evaluate the efficacy and possibly the mechanism of action of gallopamil and diltiazem in a double-blind crossover trial in patients with effort ischaemia. Twenty male patients (mean age 57 +/- 6 years) with documented coronary atherosclerosis and exercise-induced ischaemia (ST depression greater than or equal to 0.15 mV) completed the study, which consisted of four 7 day periods. At the end of each period a multistage bicycle exercise stress test was performed under placebo (first and third periods) and randomly under gallopamil (50 mg t.i.d.) or diltiazem (90 mg t.i.d.) in the second and fourth periods. Both drugs significantly increased time to ischaemia (0.15 mV ST depression) as compared to placebo, from 7.9 +/- 1.7 min to 8.9 +/- 1.1 min (diltiazem) and 9.1 +/- 1.6 min (gallopamil) with no significant difference between the two drugs, and reduced the maximal extent of ST shift from 0.18 +/- 0.08 mV to 0.13 +/- 0.04 mV (diltiazem) and 0.12 +/- 0.05 mV (gallopamil). Analysis of the results from the whole population showed that the beneficial effect did not appear to be related to any specific parameter. Individual analysis showed that 13/20 patients under gallopamil and 13/20 under diltiazem increased time to ischaemia, while this was unchanged or reduced in the remainder. A positive correlation between changes in time to ischaemia and changes in rate x pressure product at ischaemia was found in both those administered gallopamil (R 0.80, P less than 0.01) and diltiazem (R 0.65, P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Magnetic resonance tomography compared to computed tomography in the intracardiac spread of hepatocarcinoma].

A cirrhotic patient with inferior cava and right atrium-ventricular invasion by hepatic tumor was studied with transthoracic echocardiography (TTE), computerized tomography (CT) before and after contrast agent bolus iv, ECG-gated magnetic resonance imaging (MRI). Obesity obstacled abdominal echotomographic study; esophageal varices were relative contraindication to transesophageal echocardiography (TEE). The resolutive diagnosis was possible thanks to MRI which documented the spatial continuity among hepatic tumor, intracaval neoplastic thrombus and intracardiac mass. TTE can be considered the first step in case of suspected cardiac masses, but it is sometimes limited by the thorax conformation and not always discriminant. TEE is semi-invasive with important contraindications. CT is limited by the only axial or para-axial scans with low quality reconstructions, worsened in these cases by respiratory and cardiac movements. MRI can be considered the second step in the imaging of cardiac masses, immediately and directly after the echocardiographic techniques.

Carcinoma, Hepatocellular↗

[Primary malignant cardiac tumors].

Primary tumours of the heart are extremely rare, occurring in only 0.0017 to 0.28 per cent of large postmortem series. About only one-forth of all cardiac tumors are malignant. Modern techniques of diagnosis and surgical treatment have changed the benign cardiac tumor from a curiosity found at postmortem examination to an almost uniformly curable form of heart disease. Unfortunately, the same cannot be said for malignant cardiac tumors, which are both rare and almost always fatal. We reviewed the medical literature to summarize all cases of primary malignant tumors of the heart. Recently it has been pointed out that better survival in this group of patients could be a result of prompt diagnosis and treatment. Surgical intervention is rarely of benefit except for establishing a tissue diagnosis. On the contrary, survival may be enhanced by irradiation and probably by chemotherapy (sometimes as postoperative procedures).

Adult↗

[A comparison between amlodipine and nifedipine retard in patients with essential arterial hypertension].

Amlodipine, a novel dihydropyridine calcium-antagonist, was compared to slow-release nifedipine in a short-term study on 40 patients with mild to moderate essential hypertension, in order to assess the efficacy and tolerability of two different dihydropyridine calcium-antagonists with short and long half-life. After a two-week single-blind placebo period, patients were given, in a randomized sequence, amlodipine (5 or 10 mg/day od, 20 patients) or nifedipine s.r. (20 or 40 mg BID, 20 patients). At the end of treatment (12 weeks) a significant lowering of arterial pressure was obtained after 24h from the administration of amlodipin (-34/-17 mmHg) and after 12h from the administration of nifedipine s.r. (-33/-16 mmHg). Furthermore, with both drugs, no significant changes in heart rate and ECG have been reported. Amlodipine was better tolerated than nifedipine, as shown by the lower incidence of side effects. Therefore amlodipine proved to be an effective and well tolerated drug in the therapy of mild to moderate hypertension.

Adult↗

[The Study Group of Quinapril in Arterial Hypertension. The Steering Committee].

The efficacy and safety of the treatment of arterial hypertension with the ACE-inhibitor quinapril, were evaluated in a multicentre study conducted in Italy. The study, lasting 14 weeks, after a preliminary wash-out period, allowed response-based titration of quinapril dose from 10 mg to 40 mg once a day, with provision to combine additional hydrochlorothiazide (12.5 to 25 mg), in case of persistently high diastolic pressure levels. The efficacy sample included 1267 patients: at therapy week 14, 78.6% of patients were treated with quinapril alone. Global response rate (intent-to-treat) was 83.3%, with a mean reduction of diastolic pressure of 15.8 mmHg (95% confidence interval from 15.5 to 16.2 mmHg). 91 patients reported 126 associated adverse events (7.0%); the most frequently reported event was cough (2.7%). First-dose hypotension was rarely reported (1.3%), even in elderly and diabetic patients.

Angiotensin-Converting Enzyme Inhibitors↗

Thrombolysis in refractory unstable angina.

Multiple drug therapy, including nitrates, beta blockers, calcium antagonists, aspirin, and heparin, has been advocated as effective in the treatment of unstable angina, a syndrome with a multifactorial pathogenesis. Recently, plaque rupture and thrombosis have been demonstrated as the most important pathogenetic mechanisms. Nevertheless, clear-cut results on the effects of thrombolytic treatment in unstable angina are still lacking. Some possible explanations why the medical treatment of unstable angina has still not yet been standardized, whereas that of myocardial infarction has, are suggested. A review of randomized and nonrandomized studies published on this topic evaluating the role of different thrombolytic agents in unstable angina is presented. In addition the role of coronary angiography is discussed. In view of the disappointing results of coronary artery bypass surgery performed in the acute phase of the disease, one of the goals of clinical research is to identify subsets of patients at high and low risk and who undergo different types of therapeutic interventions. To support published data suggesting that total myocardial ischemia has a significant impact on prognosis, we present our results of a study carried out on patients with refractory unstable angina treated with thrombolytic therapy and evaluated with continuous electrocardiographic monitoring in the attempt to correlate total myocardial ischemia with short-term prognosis. Data in favor of the prognostic role of continuous electrocardiographic monitoring in unstable angina are also reviewed. Finally, we propose some suggestions that might be useful for future studies.

Angina, Unstable↗

Thrombolytic therapy in refractory unstable angina: the role of Holter monitoring.

We tested the safety and the usefulness of intravenous urokinase (2 million units administered over 30 min) in 44 patients with refractory unstable angina, defined as persistence of ischemic episodes during 48-h Holter monitoring (Phase 1) despite maximal medical therapy. After thrombolysis, recurrence of ischemia was observed during a week of observation in the CCU, including two 24-h Holter monitorings at the beginning and the end of the week (Phase 2). Seventeen patients completed the observation period without either symptomatic or asymptomatic ischemic episodes (Group A); the remaining 27 continued to manifest ischemia (Group B). No bleeding complications occurred. Within a 6-month follow-up, 2 patients of Group A had recurrence of unstable angina while in Group B, 19 patients had refractory angina or a major cardiac event [10 patients underwent coronary artery bypass surgery (CABG) or percutaneous transluminal coronary angioplasty (PTCA) for refractory angina (p less than 0.001), 6 other patients with refractory angina continued medical therapy, one patient had a myocardial infarction, and two patients died]. In Phase 1 the duration of total ischemia (min/24 h) was a relevant prognostic marker: higher duration correlated with adverse clinical outcome (p less than 0.01). In comparison to Phase 1, duration of total ischemia in Phase 2 was significantly reduced in both groups (16.9 +/- 19.6 vs. 25.4 +/- 17.7; p less than .001). A percent value expressing this variation was calculated for each patient: the variation thus obtained again gave information on the clinical outcome--the greater the reduction, the lower the risk of cardiac events (p less than .001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗

Cadralazine versus prazosin as second-step treatment in hypertensive patients on beta-blockers: a randomized multicentre study. The Italian Multicentre Study Group.

A randomized multicentre between-patient study comparison has been made of the efficacy and tolerability of cadralazine and prazosin, both administered for 6 weeks to hypertensive patients with a supine diastolic blood pressure (DBP) greater than or equal to 95 mmHg whilst on a beta-adrenoceptor-blocker. The doses of the beta-adrenoceptor-blocker (metoprolol SR 200 mg once daily) and cadralazine (10 mg once daily) were held constant during the study, while prazosin was individually titrated from 0.5 mg to a maximum of 2 mg tds. 108 patients (50 m and 58 f; mean age 54 y) were enrolled in 12 centres. Twelve patients withdrew due to adverse effects or poor efficacy (5 patients on prazosin and 7 on cadralazine). Both treatments induced a similar significant reduction in systolic blood pressure (SBP) and DBP, allowing normalization of BP in 58% of subjects on cadralazine and 55% on prazosin. Heart Rate (hR) increased significantly from 67 to 72 beats.min-1 in those on cadralazine and from 65 to 69 beats.min-1 on prazosin. Body weight was unchanged. Adverse effects were mild and typical of vasodilators, such as headache, flushing and dizziness. Physician evaluation of drug efficacy was not different between drugs, and cadralazine was rated better in terms of tolerability. Thus, in this multicentre study, cadralazine in the fixed dose of 10 mg once daily, as a second-step antihypertensive treatment in patients not satisfactorily controlled by a beta-adrenoceptor-blocker, was as effective and showed a similar side effect profile to prazosin given three times daily.

Adrenergic beta-Antagonists↗

Open comparative study to assess the efficacy and safety of two calcium antagonists: amlodipine and diltiazem in the treatment of symptomatic myocardial ischemia.

The efficacy and safety of amlodipine (5-10 mg once daily) and diltiazem (30-60 mg three times daily) were compared in 40 patients with symptomatic myocardial ischemia. A 2-week placebo run-in period was followed by 10 weeks of open treatment with amlodipine (n = 20) or diltiazem (n = 20). Concomitant treatment with other antianginal drugs (except other calcium antagonists) was permitted throughout the study. The baseline blood pressures were 166/93 and 160/91 mm Hg for the amlodipine group and diltiazem groups, respectively. Amlodipine (mean final daily dose of 9.25 mg) reduced blood pressure by - 27/-11 mm Hg compared with a reduction of - 17/-8 mm Hg for diltiazem (mean final daily dose of 180 mg), with no significant effects on heart rate. A significantly greater reduction in the mean rate-pressure product was observed after amlodipine (-20.8%) when compared with diltiazem (-13.1%) (p < 0.05). Amlodipine reduced the mean weekly angina attacks to zero after 6 weeks of treatment (baseline of 3.4 attacks/week) compared with a reduction from 3.3 to 0.35 attacks/week after 10 weeks of treatment with diltiazem. The amlodipine group had a reduction in mean nitroglycerin consumption from baseline of 1.1 mg/week to zero by week 6, whereas the diltiazem group had reduced mean weekly intake from 0.9 to 0.1 mg at the end of the study. The overall assessment of clinical efficacy was excellent for 100% of amlodipine patients compared with 40% of diltiazem patients. The high-density lipoprotein cholesterol/total cholesterol ratio increased by 15.8% with amlodipine compared to diltiazem, which produced a 4.5% decrease. Amlodipine decreased triglycerides by 7.1% compared to 4.5% with diltiazem. The incidence and severity of side effects was comparable for both treatments. Amlodipine once daily was effective and well tolerated in the treatment of patients with symptomatic myocardial ischemia and was comparable with diltiazem three times daily.

Adult↗

[The usefulness of echocardiography in the diagnosis of prosthetic valve endocarditis: a comparison between the transthoracic and transesophageal approaches].

Transesophageal echocardiography is a new semi-invasive procedure whose practical application has yet to be precisely defined. The diagnosis of prosthetic valve endocarditis is particularly difficult with the transthoracic approach, either by thoracic conformation of patients who underwent cardiac surgery, or ultrasound attenuation caused by the prosthetic material. Transesophageal echocardiography is useful to overcome such limits with a new acoustic window, due to the proximity of the esophagus and the heart. During 15 months 18 patients with suspected prosthetic valve endocarditis were studied using both procedures. In patients with mitral prosthetic valves, transesophageal echocardiography provided information unobtainable by using the transthoracic procedure, while in patients with aortic prosthetic valves it only showed additional information in 1 case of abscess of the posterior valve ring. In conclusion, transesophageal echocardiography is useful to diagnose all patients with suspected prosthetic mitral valve endocarditis and might be performed in patients with aortic valve prostheses if the quality of the transthoracic procedure is poor.

Aortic Valve↗

[Arterial hypertension and cardiovascular risk. Epidemiological studies, trials and therapeutic implications].

From the analysis of the epidemiological observational studies, among which one of the most famous is the Framingham study that has lasted for more than 30 years, it is evident that the risk of cardiac events and strokes is closely related to the levels of arterial systolic and diastolic blood pressure. Nevertheless, the link between hypertension and cardiovascular risk has very often been discussed, due to the results of therapeutic intervention trials, which have proved satisfactory for cardiovascular risk reduction but disappointing results for coronary disease reduction risk. Possible explanations for these poor results of antihypertensive therapy on coronary disease are different and very numerous. According to many Authors, the blood pressure was not reduced to the programmed levels in all trials and the drug used (diuretics, beta-blockers) possibly had negative effects on the lipid profile. Therefore, waiting data for new trials, will perhaps produce better results in the future taking into consideration all risks of our patient, monitoring a rigorous and steady blood pressure reduction and selecting drugs like calcium-channel blockers and ACE-inhibitors which contain characteristics similar to those ideal for the modern antihypertensive agent.

Adult↗