Exercise-based cardiac rehabilitation for coronary heart disease.

BACKGROUND: The burden of coronary heart disease (CHD) worldwide is one of great concern to patients and healthcare agencies alike. Exercise-based cardiac rehabilitation aims to restore patients with heart disease to health. OBJECTIVES: To determine the effectiveness of exercise-based cardiac rehabilitation (exercise training alone or in combination with psychosocial or educational interventions) on mortality, morbidity and health-related quality of life of patients with CHD. SEARCH STRATEGY: RCTs have been identified by searching CENTRAL, HTA, and DARE (using The Cochrane Library Issue 4, 2009), as well as MEDLINE (1950 to December 2009), EMBASE (1980 to December 2009), CINAHL (1982 to December 2009), and Science Citation Index Expanded (1900 to December 2009). SELECTION CRITERIA: Men and women of all ages who have had myocardial infarction (MI), coronary artery bypass graft (CABG) or percutaneous transluminal coronary angioplasty (PTCA), or who have angina pectoris or coronary artery disease defined by angiography. DATA COLLECTION AND ANALYSIS: Studies were selected and data extracted independently by two reviewers. Authors were contacted where possible to obtain missing information. MAIN RESULTS: This systematic review has allowed analysis of 47 studies randomising 10,794 patients to exercise-based cardiac rehabilitation or usual care. In medium to longer term (i.e. 12 or more months follow-up) exercise-based cardiac rehabilitation reduced overall and cardiovascular mortality [RR 0.87 (95% CI 0.75, 0.99) and 0.74 (95% CI 0.63, 0.87), respectively], and hospital admissions [RR 0.69 (95% CI 0.51, 0.93)] in the shorter term (< 12 months follow-up) with no evidence of heterogeneity of effect across trials. Cardiac rehabilitation did not reduce the risk of total MI, CABG or PTCA. Given both the heterogeneity in outcome measures and methods of reporting findings, a meta-analysis was not undertaken for health-related quality of life. In seven out of 10 trials reporting health-related quality of life using validated measures was there evidence of a significantly higher level of quality of life with exercise-based cardiac rehabilitation than usual care. AUTHORS' CONCLUSIONS: Exercise-based cardiac rehabilitation is effective in reducing total and cardiovascular mortality (in medium to longer term studies) and hospital admissions (in shorter term studies) but not total MI or revascularisation (CABG or PTCA). Despite inclusion of more recent trials, the population studied in this review is still predominantly male, middle aged and low risk. Therefore, well-designed, and adequately reported RCTs in groups of CHD patients more representative of usual clinical practice are still needed. These trials should include validated health-related quality of life outcome measures, need to explicitly report clinical events including hospital admission, and assess costs and cost-effectiveness.

Blood pressure lowering efficacy of beta-blockers as second-line therapy for primary hypertension.

BACKGROUND: Beta-blockers are one of the more commonly prescribed classes of anti-hypertensive drugs, both as first-line and second-line. OBJECTIVES: To quantify the effect on systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate and withdrawals due to adverse effects of beta-blocker therapy when given as a second-line drug in adult patients with primary hypertension. SEARCH STRATEGY: CENTRAL (The Cochrane Library 2009, Issue 2), MEDLINE (1966-Aug 2009), EMBASE (1988-Aug 2009) and bibliographic citations of articles and reviews were searched. SELECTION CRITERIA: Double-blind, randomized controlled trials comparing a beta-blocker in combination with a drug from another class of anti-hypertensive drugs compared with that drug alone for a duration of 3 to 12 weeks in patients with primary hypertension were included. DATA COLLECTION AND ANALYSIS: Two reviewers independently extracted the data and assessed trial quality of each included study. MAIN RESULTS: 20 double-blind RCTs evaluated the BP lowering efficacy of beta-blockers as second-line drug in 3744 hypertensive patients (baseline BP of 158/102 mmHg; mean duration of 7 weeks). The BP reduction from adding a beta-blocker as the second drug was estimated by comparing the difference in BP reduction between the combination and monotherapy groups. A reduction in BP was seen with adding a beta-blocker to thiazide diuretics or calcium channel blockers at doses as low as 0.25 times the manufacturer's recommended starting dose. The BP lowering efficacy of beta-blockers as a second drug was 6/4 mmHg at 1 times the starting dose and 8/6 mmHg at 2 times the starting dose. Beta-blockers reduced heart rate by 10 beats/min at 1 to 2 times the starting dose. Beta-blockers did not statistically significantly increase withdrawals due to adverse effects but this was likely due to the lack of reporting of this outcome in 35% of the included RCTs. AUTHORS' CONCLUSIONS: Addition of a beta-blocker to diuretics or calcium-channel blockers reduces BP by 6/4mmHg at 1 times the starting dose and by 8/6 mmHg at 2 times the starting dose. When the blood pressure lowering effect of beta-blockers from this review was compared to that of thiazide diuretics from our previous review (Chen 2009), second-line beta-blockers reduce systolic BP to the same extent as second-line thiazide diuretics, but reduce diastolic BP to a greater degree. The different effect on diastolic BP means that beta-blockers have little or no effect on pulse pressure whereas thiazides cause a significant dose-related decrease in pulse pressure. This difference in the pattern of BP lowering with beta-blockers as compared to thiazides might be the explanation for the fact that beta-blockers appear to be less effective at reducing adverse cardiovascular outcomes than thiazide diuretics, particularly in older individuals.

Blood pressure lowering efficacy of potassium-sparing diuretics (that block the epithelial sodium channel) for primary hypertension.

BACKGROUND: Potassium-sparing diuretics, which block the epithelial sodium channel (ENaC), are widely prescribed for hypertension as a second-line drug in patients taking other diuretics (e.g. thiazide diuretics) and much less commonly prescribed as monotherapy. Therefore, it is essential to determine the effects of ENaC blockers on blood pressure (BP), heart rate and withdrawals due to adverse effects (WDAEs) when given as a first-line or second-line therapy. OBJECTIVES: To quantify the dose-related reduction in systolic blood pressure (SBP) and diastolic blood pressure (DBP) of ENaC blocker therapy as a first-line or second-line drug in patients with primary hypertension. SEARCH STRATEGY: We searched CENTRAL (The Cochrane Library 2009, Issue 3), MEDLINE (1950 to August 2009), EMBASE (1980 to August 2009) and reference lists of articles. SELECTION CRITERIA: Double-blind, randomized, controlled trials in patients with primary hypertension that evaluate, for a duration of 3 to 12 weeks, the BP lowering efficacy of: 1) fixed-dose monotherapy with an ENaC blocker compared with placebo; or 2) an ENaC blocker in combination with another class of anti-hypertensive drugs compared with the respective monotherapy (without an ENaC blocker). DATA COLLECTION AND ANALYSIS: Two authors independently assessed the risk of bias and extracted data. Study authors were contacted for additional information. WDAE information was also collected from the trials. MAIN RESULTS: No trials evaluating the BP lowering efficacy of ENaC blockers as monotherapy in patients with primary hypertension were identified. Only 6 trials evaluated the BP lowering efficacy of low doses of amiloride and triamterene as a second drug in 496 participants with a baseline BP of 151/102 mm Hg. The additional BP reduction caused by the ENaC blocker as a second drug was estimated by comparing the difference in BP reduction between the combination and monotherapy groups. The addition of low doses of amiloride and triamterene in these trials did not reduce BP. An estimate of the dose-related BP lowering efficacy for ENaC blockers was not possible because of a lack of trial data at higher doses. AUTHORS' CONCLUSIONS: ENaC blockers do not have a statistically or clinically significant BP lowering effect at low doses but trials at higher doses are not available. The review did not provide a good estimate of the incidence of harms associated with ENaC blockers.

Blood pressure lowering efficacy of diuretics as second-line therapy for primary hypertension.

BACKGROUND: Diuretics are widely prescribed for hypertension not only as a first-line drug but also as a second-line drug. Therefore, it is essential to determine the effects of diuretics on blood pressure (BP), heart rate and withdrawals due to adverse effects (WDAEs) when given as a second-line drug. OBJECTIVES: To quantify the additional reduction in systolic blood pressure (SBP) and diastolic blood pressure (DBP) of diuretic therapy as a second-line drug in patients with primary hypertension SEARCH STRATEGY: CENTRAL (The Cochrane Library 2008, Issue 2), MEDLINE (1966-July 2008), EMBASE (1988-July 2008) and bibliographic citations of articles and reviews were searched. SELECTION CRITERIA: Double-blind, randomized, controlled trials evaluating the BP lowering efficacy of a diuretic in combination therapy with another class of anti-hypertensive drugs compared with the respective monotherapy (without a diuretic) for a duration of 3 to 12 weeks in patients with primary hypertension. DATA COLLECTION AND ANALYSIS: Two review authors independently extracted the data and assessed trial quality. MAIN RESULTS: Fifty-three double-blind RCTs evaluating a thiazide in 15129 hypertensive patients (baseline BP of 156/101 mmHg) were included. Hydrochlorothiazide was the thiazide used in 49/53 (92%) of the included studies. The additional BP reduction caused by the thiazide as a second drug was estimated by comparing the difference in BP reduction between the combination and monotherapy groups. Thiazides as a second-line drug reduced BP by 6/3 and 8/4 mmHg at doses of 1 and 2 times the manufacturer's recommended starting dose respectively. The BP lowering effect was dose related. The effect was similar to that obtained when thiazides are used as a single agent. Only 3 double-blind RCTs evaluating loop diuretics were identified. These RCTs showed a BP lowering effect of a starting dose of about 6/3 mmHg. AUTHORS' CONCLUSIONS: Thiazides when given as a second-line drug have a dose related effect to lower blood pressure that is similar to when they are added as a first-line drug. This means that the BP lowering effect of thiazides is additive. Loop diuretics appear to have a similar blood pressure lowering effect as thiazides at 1 times the recommended starting dose. Because of the short duration of the trials and lack of reporting of adverse events, this review does not provide a good estimate of the incidence of adverse effects of diuretics given as a second-line drug.

Harnessing innate lung anti-cancer effector functions with a novel bacterial-derived immunotherapy.

Acute infection is known to induce strong anti-tumor immune responses, but clinical translation has been hindered by the lack of an effective strategy to safely and consistently provoke a therapeutic response. These limitations are overcome with a novel treatment approach involving repeated subcutaneous delivery of a Klebsiella-derived investigational immunotherapeutic, QBKPN. In preclinical models of lung cancer, QBKPN administration consistently showed anti-cancer efficacy, which was dependent on Klebsiella pre-exposure, but was independent of adaptive immunity. Rather, QBKPN induced anti-tumor innate immunity that required NK cells and NKG2D engagement. QBKPN increased NK cells and macrophages in the lungs, altered macrophage polarization, and augmented the production of cytotoxic molecules. An exploratory trial in patients with non-small cell lung cancer demonstrated QBKPN was well tolerated, safe, and induced peripheral immune changes suggestive of macrophage polarization and reduction of PD-1 and PD-L1 expression on leukocytes. These data demonstrate preclinical efficacy, and clinical safety and tolerability, for this cancer immunotherapy strategy that exploits innate anti-tumor immune mechanisms.