2 Minute Medicine Rewind August 11 – August 18, 2013

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In this section, we will highlight the key high-impact studies, updates, and analyses published in medicine during the past week. 

Long-Term Survival of Participants in the Prostate Cancer Prevention Trial

The Prostate Cancer Prevention Trial (PCPT), a randomly controlled trial conducted from 1994-2004involving 18,882 men randomized to receive either finasteride or placebo, demonstrated that finasteride reduced the relative risk of prostate cancer by 24.8% but showed a relative increase of 26.9% for the risk of high-grade prostate cancer. In this follow-up analysis, researchers collected data on the incidence of prostate cancer among PCPT patients for an additional year after the PCPT’s conclusion and looked at differences in all-cause and prostate-cancer mortality through 2011.  Finasteride reduced the overall risk of prostate cancer (10.5% vs. 14.9%, relative risk 0.70, 95% CI 0.65-0.76, P<0.001) and increased the risk of high-grade prostate cancer(3.5% vs. 3.0%,  relative risk 1.17, 95% CI 1.00-1.37, P=0.05). However, it had no significant effect on overall survival in prostate cancer patients after 18 years of follow-up (15-year survival 78.0% vs. 78.2%, HR 1.02, P=0.46).

Cardioprotective and prognostic effects of remote ischaemic preconditioning in patients undergoing coronary artery bypass surgery: a single-centre randomised, double-blind, controlled trial

Small trials have shown a decrease in the release of myocardial injury biomarkers after various cardiac procedures for patients who undergo remote ischemic precondition using short periods of induced ischemia followed by reperfusion.  In this randomized controlled trial, 329 patients undergoing triple-vessel coronary artery bypass surgery (CABG) were assigned to receive ischemic preconditioning or no preconditioning, with the primary outcome being perioperative concentrations of cardiac troponin I (cTnI) measured by the geometric mean area under the curve (AUC) in the first 72 hours after CABG.  The ratio of cTnI AUC in the intervention to control group was 0.83 (95% CI 0.70-0.97, P=0.022) in the intention-to-treat analysis and 0.79 (85% CI 0.66-0.94, P=0.001) in the per-protocol analysis.  All-cause mortality over 1.54 years was lower in the intervention group (ratio 0.27, 95% CI 0.08-0.98, P=0.046). Remote ischemic preconditioning appears to provide perioperative myocardial protection and significantly reduces the mortality of patients undergoing CABG.

The State of US Health, 1990-2010.  Burden of Diseases, Injuries, and Risk Factors

The report from the Global Burden of Disease 2010 study is a systematic analysis of the epidemiology of 291 disease and injuries in the US, with calculated outcomes being years of life lost due to premature mortality (YLLs), years lived with disability (YLDs), disability-adjusted life-years (DALYs), and healthy life expectancy (HALE).  Investigators found that US life expectancy increased from 75.2 years in 1990 to 78.2 years in 2010 with the HALE improving from 65.8 years to 68.1 years.  Diseases that caused the greatest YLLs were ischemic heart disease, lung cancer, stroke, chronic obstructive pulmonary disease, and road injury.  Conditions that caused the greatest YLDs were low back pain, major depressive disorder, other musculoskeletal disorders, neck pain, and anxiety disorders.  Among the 34 OECD countries, the US’s progress in improving population health was comparatively slower and its ranked dropped from 18 to 27 for death rate, 23 to 28 for YLL rate, 5 to 6 for YLD rate, 20-27 for life expectancy, and 14 to 26 for HALE.

Percutaneous vesicoamniotic shunting versus conservative management for fetal lower urinary tract obstruction (PLUTO): a randomised trial

Fetuses with lower urinary tract obstruction (LUTO) have high perinatal and long-term mortality and morbidity.  Vesicoamniotic shunting has been proposed as a possible treatment.  In this randomized trial, 31 patients with singleton pregnancies complicated by LUTO were assigned to receive either vesicoamniotic shunting or conservative management with the primary outcome being survival of the baby to 28 days postnatally.  Of the 16 pregnancies that received the intervention, 8 neonates survived to 28 days compared to 4 of the 15 pregnancies that received conservative management (intention-to-treat relative risk 1.88, 95% CI 0.71-4.96, P=0.27; per-protocol relative risk 3.20, 95% CI 1.06-9.62, P=0.03).  This study was closed early because of poor recruitment and could not conclusively show a benefit.  Results trended towards increased survival in the intervention group, but there was still very high morbidity and mortality.

Faldaprevir and Deleobuvir for HCV Genotype 1 Infection

Because of the significant adverse effects associated with interferon, interferon-free regimens for the treatment of chronic hepatitis C virus (HCV) infection are highly desirable.  In this phase 2, randomized open-label trial, 362 patients were assigned to receive one of 5 different dosing regimens that included faldaprevir (a protease inhibitor) and deleobuvir (a nonnucleoside polymerase inhibitor) with ribavirin (named TID16W, TID28W, TID40W, or BID28W) or without ribavirin (named TID28W-NR).  The primary outcome was sustained virologic response 12 weeks after completing therapy.  In the non-ribavirin groups, the primary endpoint was met in 59%, 59%, 52%, and 69% of the patients for the TID16W, TID28W, TID40W, and BID28W groups respectively, compared with 39% of patients in the TID28W-NR group, with a statistically significant difference between the TID28W and TID28W-NR groups (P=0.03).  Faldaprevir combined with deleobuvir appears to be an effective interferon-free treatment for chronic HCV infection, demonstrating sustained virologic response 12 weeks after therapy completion for 52-69% of patients.

By Neal Yuan and David Ouyang

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