Antithrombotic therapies could protect elderly from cold weather CVD deaths

An increased thrombotic tendency during the winter months could explain the increased CV morbidity and mortality observed during the same time period, finds a UK abstract (number P521). The thrombotic tendency, suggest the investigators, might potentially be preventable by prescribing antithrombotic therapies to elderly patients. In Great Britain, according to the Office of National Statistics, there is known to be a 15 % excess of CV deaths during December to March compared with April to November among men aged 65 to 84 years. Other studies have suggested that this pattern of excess winter mortality is common in southern as well as northern European countries. In an attempt to explain the “winter effect” Richard Morris and colleagues, from University College (London, UK) investigated the haemostatic variables known to be associated with CHD incidence. In the study 4088 men aged between 60 and 79 years, from 24 towns across Britain, were examined between January 1998 and March 2000 for the following biochemical measures: tissue plasminogen activator (t-PA), von Willebrand Factor (vWF) and fibrin D-Dimer. Although each participant provided only one measurement, all the months of the year were represented by an average of over 300 participants per month. The investigators produced a cosinor analysis, where curves shaped like waves depicted changes in each measure over the course of the year. The results showed that all three markers peaked in the winter months, with vWF and D-Dimer peaking in December and t-PA in January. The difference in mean between winter and non-winter months was 0.92ng/mL for t-PA, 6.82 IU/dL for vWF and 0.103 ng/mL for D-Dimer, after adjustment for relevant confounding factors. These results, the investigators calculated, would lead to an overall 9.1% excess CHD mortality in winter. “Older people whose risk of CHD is already high might potentially be protected by interventions to lower their risk during cold weather,” suggested Morris, adding that the study needs to be replicated and undertaken in women. “If the hypothesis still seems to stand, studies should evaluate suitable interventions to assess the benefits of reducing haemostasis in winter months among people considered at high risk.” *ESC