Congestive heart failure (CHF) is a chronic progressive disease with physical symptoms such as shortness of breath, non-specific fatigue and fluid retention. Definitive diagnosis normally relies on functional investigations such as ECG and chest X-rays, as well as cardiac imaging, particularly color Doppler echocardiography.As a more rapid lower-cost approach, measurement of plasma levels of natriuretic peptides provides input that correlates well with the medical severity of CHF. This helps in the initial diagnosis, and also in monitoring the effectiveness of subsequent therapeutic management.
A number of ELISA-based assays have been developed which do not require sample extraction, from CIS-BIO (Gif-sur-Yvette, France) and Bachem Peninsular Laboratories (Belmont, California), among others. Both of these assays are directed to B-type natriuretic peptide (BNP) specifically because of its higher plasma level in CHF. BioSite Diagnostics (Velizy, France) has launched a simple rapid point-of-care test for BNP. The Triage test can be used on whole blood or plasma samples, with results in 15 minutes.
Some assays have been developed that measure the inactive N-terminal portion of the active peptide, because of its longer half-life in plasma. Roche Diagnostics (Mannheim, Germany) and Biomedica Medizinprodukte (Vienna, Austria) both have launched assays to measure NTproBNP in serum or plasma. This is the N-terminal residue of the proBNP precursor molecule, which splits to form NTproBNP and BNP. Roche has developed its test to run on the Elecsys automated immunoassay analyzer and claims a negative predictive value of 98%. The Biomedica assay is a competitive enzyme assay (EIA) and is claimed to have a sensitivity of down to 5 fmol/ml.
Elevated total homocysteine concentrations are generally regarded as major risk factors for thrombosis and atherosclerosis. While it has been accepted for some time that homocysteinuria, a rare inborn error of metabolism, is usually due to genetic mutations, it also has been suggested that milder, but more common genetic mutations in the same enzymes could contribute to increased plasma homocysteine levels.
Tiziana de Cristofaro and her group at the Federico II University Medical School (Naples, Italy) have investigated several common mutations of genes of the homocysteine pathway and their results support the hypothesis that homozygosity for C677T MTHFR mutation is a risk factor for the development of venous thromboembolism.
Cerebral bleeding after stroke
Patients with a history of microbleeds in the brain are seven times more likely than others to develop cerebral bleeding (CB) after a stroke. Norbert Nighogossian, professor of neurology at the Hopital Neurologique (Lyon, France) and his group suggested in a recent paper in Stroke that the use of microbleeds as a marker for serious stroke complications may help physicians to identify patients who need to be treated more cautiously.
Old microbleeds can indicate that small blood vessels are diseased, a situation potentially made worse by hypertension, diabetes and long-term use of anti-clotting therapy. "I urge practitioners to carefully manage patients with diabetes and hypertension because they could be at increased risk of microbleeds and for cerebral bleeding," Nighogossian said.
To detect previous microbleeds, the researchers used a new imaging technique called T2-weighted gradient-echo magnetic resonance imaging. This technique is more sensitive than conventional MRI, which can fail to detect CB at an early stage of stroke.
Stroke risks cut in AF patients
Around 90% of nonrheumatic atrial fibrillation (AF)-related strokes result from a blood clot forming in the left atrial appendage, a small pouch in the left upper chamber of the heart, according to Horst Sievert, senior consultant at the Cardiovascular Center of the Bethanien Krankenhaus (Frankfurt, Germany). "The left atrial appendage has no purpose. Nobody needs it," he said. "Its only function is to form clots. It can be blocked with no disadvantage to the patient."
Sievert and his team have recently published results of sealing off the left atrial appendage in 15 chronic AF patients with a blocking device placed with a catheter guided by transesophageal echocardiography. The study, reported in Circulation, describes the blocking device as a self-expanding nitinol cage that automatically opens as the metal warms up to body temperature. The device has a membrane cover that both blocks the atrial appendage and allows tissue ingrowth to seal the blockage.
The PLAATO (percutaneous left atrial appendage transcatheter occulusion) procedure has been carried out on 15 patients, with no strokes and no subsequent complications at six months' follow-up, Sievert said.
After 14 years, a decision in France
In 1988 the first legal actions were taken by the French Association des Polytransfus s (multiple transfusions) against the French blood transfusion service (CNTS) for having provided HIV-contaminated blood and blood products in 1985 and, as a result, infected in excess of 100 hemophiliac patients.The then-director of the CNTS, Michel Garretta, was sentenced in 1992 to four years in prison and a fine of Fr 500,000. Two other physicians also were found guilty. A total of around 30 physicians and technicians were investigated.
In 1994, the files were re-opened after a controversial decision by the Court of Appeal, with the enquiry widened to include not only senior civil servants and their advisers, but also top management at Diagnostics Pasteur (Paris), a leading French clinical diagnostics manufacturer whose HIV screening test was favored over that of Abbott Laboratories (Abbott Park, Illinois).
Last month the Court of Appeal, in a surprise decision, announced a "non-lieu g n ral" (no grounds for prosecution), finally closing the files. Oliver Duplessis, president of the Association Francaise des Transfus s said after the decision, "The proof is today established that French justice does not dare pursue those responsible for major healthcare scandals."
Statin therapy continuation urged
Physicians at the Kerckhoff Heart Center (Bad Nauheim, Germany) have published a study in Circulation recommending that patients already taking cholesterol-lowering statin drugs should continue their medication even when hospitalized for chest pain.
In examining medical records of more than 1,600 heart patients, they found that the risk of death or non-fatal heart attack for patients who were not continued on statin drugs after hospital admission was almost three times that of patients who continued the therapy. In addition, a significant number who were taken off their medication had to undergo procedures to restore blood flow in their coronary arteries.
The researchers conclude that statins appear to do more than just lower cholesterol. They also reduce inflammation and the proliferation of smooth muscle cells in the arteries and increase the release of protective nitric oxide from heart cells.
"There was no evidence that the discontinuation of the statins was related to the risk profile of the patients," said Christian Hamen, a study author. "Risk factors, including baseline cholesterol levels and troponin T levels at the beginning of the study were similar in patients remaining on statins and those who stopped taking statins after admission."