Primum non nocere

Hipócrates, ao redor do ano 430 aC, propôs aos médicos, no parágrafo 12 do primeiro livro da sua obra Epidemia:
"Pratique duas coisas ao lidar com as doenças; auxilie ou não prejudique o paciente" - ou seja, primum non nocere - primeiro de tudo, não provoque nenhum dano.

sexta-feira, 16 de maio de 2008

Finasterida reduz o risco de câncer de próstata

Thompson IM et al. Does the level of prostate cancer risk affect cancer prevention with finasteride?. Urology. 2008 May;71(5):854-7.

O medicamento finasterida significativamente reduz o risco de câncer de próstata em 24,8% de acordo com o estudo Prostate Cancer Prevention Trial (PCPT), entretanto algumas questões referentes ao seu mecanismo de ação estavam abertas.

O presente estudo é um acompanhamento de mais de 7 anos desse estudo inicial e a finasterida continuou prevenindo o câncer de próstata, mesmo naqueles pacientes com alto risco para o desenvolvimento de câncer, mostrando que o seu efeito não só é preventivo, quanto é terapêutico.

Portanto, se você é homem, está na faixa de risco (acima de 55 anos) e ainda tem próstata, converse com seu médico se ele tem ciência desse estudo e se deveria usar finasterida entre 1mg a 5mg, diariamente.

quinta-feira, 15 de maio de 2008

Utilidade do tratamento com Dinitrato de Isossorbida em pacientes com urgências hipertensivas.

Álvarez DR. Utilidad del tratamiento con Dinitrato de Isosorbide en pacientes con urgencias hipertensivas. Revista Electronica de PortalesMedicos. Online Publication, 12 May 2008.

O dinitrato de isossorbida por via sublingual associado ao captopril 50mg por via oral é tão eficaz quanto à associação captopril 50mg e nifedipina 10mg, entretanto obtém controle mais rápido dos níveis tensionais em pacientes com urgências hipertensivas.


Se realizó una investigación prospectiva no experimental, longitudinal de cohorte acerca del uso del Dinitrato de isosorbide oral en la urgencia hipertensiva pudiendo correlacionar su uso con la nifedipina y el captopril, medicamentos de eficacia comprobada en el tratamiento de la urgencia hipertensiva. Se estudiaron 120 pacientes con este diagnóstico, distribuidos aleatoriamente en tres grupos, los cuales recibieron 10 miligramos de nifedipina o dinitrato de isosorbide y 50 miligramos de captopril.

Se pudo constatar que a los que se le administró dinitrato de isosorbide se logró un control más rápido de su tensión arterial que a los que se les administraron los otros dos fármacos. La cefalea constituyó la reacción adversa más frecuente. Una vez más nos encontramos frente a una alternativa de tratamiento efectiva e inocua para minimizar los síntomas de la urgencia hipertensiva y evitar las complicaciones que de ella se derivan cuando alargamos el tiempo para llevar la tensión arterial a los niveles normales. Por lo tanto sugerimos que se realicen estudios similares en cuanto a la utilización de este fármaco en la urgencia hipertensiva por su valor y los pocos efectos adversos que ocasiona su uso.

Biomarcadores melhoram a predição de morte cardiovascular em homens idosos

Zethelius B. et AL. Use of Multiple Biomarkers to Improve the Prediction of Death from Cardiovascular Causes. NEJM. May 15, 2008;358(20):2107-2116.

A incorporação de 4 biomarcadores (troponina, peptídeo natriurético cerebral, cistatina C e proteína C reativa) aos fatores usuais de avaliação de risco cardiovascular significativamente aumenta a previsibilidade de morte por causas cardiovasculares


Incorporating four biomarkers along with the usual factors in assessing cardiovascular risk significantly increases the predictability of death from cardiovascular causes, the New England Journal of Medicine reports.

Researchers used customary risk factors, plus four biomarkers, to evaluate a cohort of some 1100 men with a mean age of 71 years. The biomarkers chosen reflect damage to or malfunction of various systems — namely, myocardium (troponin), left ventricle (brain natriuretic peptide), kidney (cystatin C), and inflammation (C-reactive protein).

After 10 years' follow-up, the inclusion of biomarkers significantly increased the predictability of death from cardiovascular disease, both in the entire cohort and in those without cardiovascular disease at baseline. Those with elevations in any two biomarkers had a 3-fold increase in risk, and elevations in all four presaged a 16-fold increase.

Editorialists say the results need validation in younger cohorts that include both men and women who don't have cardiovascular disease.

57th Annual Scientific Sessions of the American College of Cardiology

Apresentação de vários ensaios clínicos no Encontro Anual do Colégio Americano de Cardiologia em Chicago IL de 30 de Março a 02 de Abril de 2008, incluindo os ensaios ONTARGET, ACCOMPLISH, ENHANCE e (JUPITER).


JUPITER examined the role of rosuvastatin (20 mg/day) in the primary prevention of cardiovascular disease among patients with low levels of LDL-cholesterol and elevated high-sensitivity C-reactive protein.

The trial was stopped early as evidence clearly showed a reduction in cardiovascular morbidity and mortality in patients treated with rosuvastatin compared with placebo.

Full study details to be published once final analysis of data is complete.

STUDY OUTCOMES:

Over 5,000 patients without evidence of cardiovascular disease and low to normal LDL-C, but elevated C-reactive protein were enrolled in the trial. The trial was stopped early based on a recommendation from an independent Data and Safety Monitoring Board due to unequivocal evidence of a reduction in cardiovascular morbidity and mortality in patients treated with rosuvastatin compared with placebo.

ONTARGET enrolled 25,620 high risk subjects aged > 55 with either established vascular disease or DM and end-organ damage into a large international randomized trial of angiotensin modulating therapy. Subjects received either ramipril 10 mg, telmisartan 80 mg or the full dose combination daily. Over a mean follow up of 56 months, telmisartan was found to be statistically non-inferior, clinically equivalent and better tolerated than ramipril while the combination was no better than ramipril alone but with greater side-effects! The results were consistent for all major components of the primary end-point, including myocardial infarction, stroke, heart failure hospitalisation and cardiovascular death and across all pre-defined patient subgroups (age, gender, risk, BP, DM, Hx of CAD). Physicians now have a choice between an ACE inhibitor or an ARB in CVD prevention in the “HOPE-type” patient.

STUDY OUTCOME:

Telmisartan was found to be statistically non-inferior, clinically equivalent and better tolerated than ramipril while the combination was no better than ramipril alone but with greater side-effects.

ACCOMPLISH examined the role of amlodipine/benazapril (5 mg/40 mg), compared with hydrochlorothiazide (HCTZ)/benazapril (12.5 mg/40 mg) in reducing cardiovascular morbidity and mortality in high-risk patients with systolic hypertension.
The trial was stopped early with a finding of a 20% reduction in many of the primary endpoints with amlodipine/benazapril compared with HCTZ/benazapril

STUDY OUTCOME:

Trial was terminated early due to a finding of a 20% reduction in the primary endpoint of cardiovascular mortality, stroke, myocardial infarction (MI), coronary revascularization, unstable angina, and resuscitation from death in the amlodipine/benazapril arm compared with the HCTZ/benazapril arm (p = 0.002). Cardiovascular death, stroke, and MI was also reduced by 20% (p = 0.007). All other endpoints, including cardiovascular mortality, nonfatal MI, nonfatal stroke, and resuscitated sudden death were similar between the two groups.


Beta-Bloqueadores no peri-operatório aumentam os riscos após cirurgia não-cardíaca

POISE Study Group. Effects of extended-release metoprolol succinate in patients undergoing non-cardiac surgery (POISE trial): a randomised controlled trial. The Lancet Early Online Publication, 13 May 2008

Beta-bloqueador – especificamente succinato de metoprolol, único usado no estudo – aumenta o risco de acidente vascular cerebral e morte não-cardiovascular.


In an international, double-blind, industry-supported study, some 8350 patients with (or at risk for) atherosclerotic disease were randomized preoperatively to a 30-day regimen of extended-release metoprolol or placebo. Patients already receiving beta-blockers were excluded.

By 30 days, patients on metoprolol showed favorable results for the primary endpoint (a composite of cardiovascular death, nonfatal MI, and nonfatal cardiac arrest) — but they had significantly higher rates of death and stroke.

The authors write that current perioperative guidelines ought to be reconsidered. Commentators agree that the regimen used carries more risk than benefit; however, they recommend a lower-dose long-acting regimen that is "titrated to effect" at least 7 days before surgery. That regimen, they say, "is associated with overall benefit compared to risk."

Asked to comment, Journal Watch Cardiology editor-in-chief Harlan Krumholz says that using extended-release metoprolol to reduce risk in patients undergoing noncardiac surgery "has suddenly become a lot more controversial than it was yesterday. If this strategy is contemplated, then it should be done with the patient's knowledge of the potential trade-offs in outcomes."


segunda-feira, 12 de maio de 2008

Achados na tomografia computadorizada do crânio pode predizer derrame após isquemia transitória

Sciolla R, Melis F; SINPAC Group. Rapid identification of high-risk transient ischemic attacks: prospective validation of the ABCD score.Stroke. 2008 Feb;39(2):297-302. Epub 2008 Jan 3.

Ataques isquêmicos transitórios (AIT) determinam um alto risco no curto prazo de acidente vascular cerebral (AVC) definido, entretanto, é dificil distinguir entre os pacientes com isquemias transitórias que evoluirão para um AVC definido.

O desenvolvimento de um escore ABCD de 6 pontos parece clarear essa indefinição: (Age (idade) ≥60 anos = 1 ponto; Blood pressure (pressão arterial ) ≥140/90 mm Hg = 1 ponto; Clinical features (apresentação clínica): perda de força unilateral = 2 pontos e dificuldade para falar sem perda de força = 1 ponto; e Duration (duração) de ≥60 minutos = 2 pontos ou 10 a 59 minutos = 1 ponto). Esse escore prediz o risco de AVC em ambos 7 dias e 1 mês. Altos escores (>/=4) progressivamente conferem um alto risco de AVC subsequente, sendo que aqueles que tem escore <4 não tem AVC dentro de um mês. Achados de imagens de CT de crânio (evidência de doença na substância branca ou infarto cerebral = 1 ponto) cria o escore ABCDi o qual reforça as predições: Um escore ABCD de 5 ou 6 confere um aumento em 6x do risco de AVC em 7 dias e 1 mês, enquanto que o escore ABCDi de 5 ou 7 confere um aumento no risco de 11x. Esse escore com a adição de diabetes (ABCD2) aumenta ainda mais a identificação dos pacientes com AIT que necessitam de pronta e intensiva redução do risco vascular.

Placa carotídea: um precursor subclínico de eventos vasculares

Espessura máxima da placa carotídea é um simples e não invasivo marcador de aterosclerose subclínica associada com risco aumentado de eventos vasculares.

Rundek T, ArifMcCord H et al. Carotid plaque, a subclinical precursor of vascular events

The Northern Manhattan Study. NEUROLOGY 2008;70:1200-1207.

Carotid atherosclerosis is a known biomarker associated with future vascular disease. The risk associated with small, nonstenotic carotid plaques is less clear. The objective of this study was to examine the association between maximum carotid plaque thickness and risk of vascular events in an urban multiethnic cohort.

As part of the population-based Northern Manhattan Study, carotid plaque was analyzed among 2,189 subjects. Maximum carotid plaque thickness was evaluated at the cutoff level of 1.9 mm, a prespecified value of the 75th percentile of the plaque thickness distribution. The primary outcome measure was combined vascular events (ischemic stroke, myocardial infarction, or vascular death).

Carotid plaque was present in 1,263 (58%) subjects. After a mean follow-up of 6.9 years, vascular events occurred among 319 subjects; 121 had fatal or nonfatal ischemic stroke, 118 had fatal or nonfatal myocardial infarction, and 166 died of vascular causes. Subjects with maximum carotid plaque thickness greater than 1.9 mm had a 2.8-fold increased risk of combined vascular events in comparison to the subjects without carotid plaque (hazard ratio, 2.80; 95% CI, 2.04–3.84). In fully adjusted models, this association was significant only among Hispanics. Approximately 44% of the low-risk individuals by Framingham risk score had a 10-year vascular risk of 18.3% if having carotid plaque.

Conclusions: Maximum carotid plaque thickness is a simple and noninvasive marker of subclinical atherosclerosis associated with increased risk of vascular outcomes in a multiethnic cohort. Maximum carotid plaque thickness may be a simple and nonexpensive tool to assist with vascular risk stratification in preventive strategies and a surrogate endpoint in clinical trials.

Prescrevendo beta-bloqueadores em pacientes idosos com insuficiência cardíaca

Galinier M and Emeriau JP. Prescribing beta blockers in elderly patients with heart failure. Presse Med. 2008 Apr 29 - Epub ahead of print.

Os beta-bloqueadores são ambos eficazes e bem tolerados em pessoas idosas com insuficiência cardíaca, independente da sua fração de ejeção, entretanto, os protocolos prescritivos devem ser seguidos estritamente – Estudo SENIORS.

Beta blockers remain underused in elderly patients with heart failure. Age is not a contraindication to beta blockers. The SENIORS study confirmed that beta blockers are both efficacious and well tolerated in elderly people with heart failure, regardless of their ejection fraction. Because adverse effects may be both more frequent and more serious in the elderly, prescription protocols must be strictly applied. Patients in stable NYHA stages II or III may begin beta blocker treatment, at least 1 month after any decompensation. The initial dose must be as low as possible (1.25mg/d for bisoprolol and nebivolol). Doses must be increased very progressively and stages longer than 15 days may be necessary. The objective is to reach the target dose (10mg/d for bisoprolol and nebivolol), given the dose-response effect that exists for beta blockers in elderly people with heart failure. In the case of low blood pressure, antihypertensive treatments must be reduced or stopped (for example, nitrate derivatives or calcium channel blockers). A reduction in the dosage of any diuretic dosage and finally of the beta blocker may follow, if necessary. Should bradycardia occur, any anti-bradycardia treatments (such as digoxin or amiodarone) must be reduced or stopped before the beta blocker dosage is reduced.