Cochrane Heart Group Research Articles

Assessment of analysis by gender in the Cochrane reviews as related to treatment of cardiovascular disease.

Cardiovascular disease (CVD) is the leading killer of women in the United States, yet medical care is often based on evidence from clinical trials performed predominantly with men. Numerous studies show that CVD risk factors, clinical presentation, treatment, and treatment outcomes can vary between men and women. The Cochrane Library maintains a large database of critically appraised evidence including meta-analyses of clinical trials, called Systematic Reviews. There were 30 Systematic Reviews pertaining to the treatment of CVD published collectively by the Cochrane Heart Group, Hypertension Group, and Peripheral Vascular Diseases Groups at the time of our study. We examined these 30 Systematic Reviews and the great majority of the clinical trials used for their meta-analyses for inclusion of women and gender-based data analyses. Women comprised only 27% of the pooled population of 258 clinical trials. Of those trials that included both men and women (n = 196), only 33% examined outcomes by gender. In trials that performed a gender-based analysis, 20% reported significant (p < 0.05) differences in cardiovascular-related outcomes by gender. We conclude that (1) there are not enough large-scale clinical trials or meta-analyses concerning CVD in women to determine if their medical treatment should differ from that of men, (2) all clinical trials relating to CVD treatment should have significantly more female participants, and gender-based analyses should be performed, as currently recommended for National Institutes of Health (NIH)-sponsored research by the NIH Revitalization Act of 1993, and (3) the Cochrane Library would be a more useful tool for the evidence-based healthcare of women if the Systematic Reviews used all available gender-specific information in their analyses.

Heroes and evidence

J Thorac Cardiovasc Surg 2002;124:11-3

Active chest compression-decompression for cardiopulmonary resuscitation.

Active compression-decompression cardiopulmonary resuscitation (ACD CPR) uses a hand-held suction device, applied mid sternum, to compress the chest then actively decompress the chest after each compression. Randomised controlled trials on use of active compression decompression cardiopulmonary resuscitation have results which are discordant. To determine clinical effects and safety of active compression-decompression cardiopulmonary resuscitation compared with standard manual cardiopulmonary resuscitation (STR). We searched the Cochrane Heart Group Specialised register (April 2001), the Cochrane library, MEDLINE and EMBASE. We checked the reference list of retrieved articles and contacted enterprises manufacturing the active decompression devices. All randomized or quasi-randomized studies comparing active compression-decompression cardiopulmonary resuscitation compared with standard manual cardiopulmonary resuscitation in adults with a cardiac arrest who received cardiopulmonary resuscitation by a trained medical or paramedical team. Data were independently extracted. All data were analysed on an intention-to-treat basis. The authors of the primary studies were contacted for more information when needed. Studies were cumulated, if appropriate, and pooled relative risk (RR) estimated. Subgroup analysis according to setting (out of hospital or in hospital) and attending team composition (with physician or paramedic only) were predefined. Twelve trials were included: 10 were in out-of-hospital settings, one set in-hospital only and one had both in-hospital and out-of-hospital components. Allocation concealment was adequate in 4 trials. The two in-hospital studies were very different in quality (A and C) and size (773 and 53 patients). Both found no differences between ACD CPR and STR in any outcome. Trials conducted in out-of-hospital settings cumulated 4162 patients. There were no differences between ACD CPR and STR for mortality either immediately (RR 0.98 [95% CI 0.94 - 1.03]) or at hospital discharge (RR 0.99 [95% CI 0.98 - 1.01]). The pooled RR of neurological impairment, any severity, was 1.71 [95% CI 0.90 - 3.25], with a non-significant trend to more frequent severe neurological damage in survivors of ACD CPR (RR 3.11 [95% CI 0.98 - 9.83]). However, assessment of neurological outcome was limited and there were few patients with neurological damage. There was no difference between ACD CPR and STR with regard complications such as rib or sternal fractures, pneumothorax or hemothorax (RR 1.09 [95% CI 0.86 - 1.38]). Skin trauma and ecchymosis were more frequent with ACD CPR. Active chest compression-decompression in patients with cardiac arrest is not associated with clear benefit.

Mediastinal chest drain clearance for cardiac surgery

Cardiac tamponade may occur following cardiac surgery as a result of blood or fluid collecting in the pericardial space compressing the heart and reducing cardiac output. Mediastinal chest drains (including pericardial drains) are inserted as standard post-operative practice following cardiac surgery to assist the clearance of blood from the pericardial space and to prevent cardiac tamponade. To prevent chest tubes from blocking and so causing tamponade nurses manipulate them to prevent or remove clots. Manipulation methods including milking, stripping, fanfolding and tapping may be applied to the tubes to keep them from blocking. Evidence is required as to the safest and most effective means of preventing chest tube blockage and preventing cardiac tamponade. To compare different methods of chest drain clearance (i.e. varying levels of suction or suction in combination with milking, stripping, fanfolding and tapping of chest drains) in preventing cardiac tamponade in patients following cardiac surgery. Over both the initial review and the 2004 revision, we searched the Cochrane Heart Group trials register, the Cochrane Controlled Trials Register (CCTR) (Issue 4, 2003) The Cochrane Database of Systematic Reviews (CDSR), the Database of Abstracts of Reviews of Effectiveness (DARE), Issue 4, 2003, MEDLINE (1966 to Nov Week 2, 2003), EMBASE (1980 to 2003 Week 47), CINAHL (1982 to Nov 2003), the Clinical Trials site of the NIH, (USA) (24.11.03) and reference lists of articles. Randomised, quasi-randomised or systematically allocated clinical trials of chest tube manipulation methods in adults and children with mediastinal chest drains following cardiac surgery were included. Two reviewers independently assessed trial quality and extracted data. Study authors were contacted for additional information where required. Adverse effects information was collected from the trials. Three studies with a total of 471 participants were included. There was no data, however, which could be included in a meta-analysis. This was due to inadequate data provision by two of the studies. Where adequate data were provided there were no common interventions or outcomes to pool. On the basis of single studies there was no evidence of a difference between groups on incidence of chest tube blockage, heart rate, cardiac tamponade or incidence of surgical re-entry. There are insufficient studies which compare differing methods of chest drain clearance to support or refute the relative efficacy of the various methods in preventing cardiac tamponade. Nor can the need to manipulate chest drains be supported or refuted by results from RCT's.