Int J Clin Lab Res (1999) 29:141-144 © Springer-Verlag 1999 R. Pellicano • M.G. Mazzarello • S. Morelloni M. Allegri • V. Arena • M. Ferrari • M. Rizzetto A. Ponzetto Acute myocardial infarction and Helicobacter pylori seropositivity Received: 19 June 1999 / Accepted: 15 November 1999 Abstract Infectious agents including Helicobacter pylori, have been linked to coronary heart diseases on epidemiological and pathogenetic grounds. Classical risk factors fail to explain all the epidemiological variations of the disease. Our aim was to investigate the association of acute myocardial infarction with Helicobacter pyIori infection in a case-control study by comparing a group of male patients with a control group of blood donors matched for sex and age. We investigated the classical cardiovascular risk factors in all patients. We studied 44 consecutive male patients, aged 40-65 years, admitted for acute myocardial infarction to the Coronary Care Unit at Novi Ligure Hospital in northern Italy. Helico- bacter pylori infection was assessed by measurement of antibodies (IgG) against Helicobacter pylori in blood. Volunteer blood donors attending Molinette Hospital Blood Bank in Turin, northern Italy served as controls. Among the patients we investigated the presence of hy- pertension, cholesterol and glucose levels in serum, fi- brinogen in plasma, smoking habits, and social class. Helicobacter pylori infection was present in 34 of 44 (77%) patients and in 183 of 310 (59%) controls (P<0.05); the odds ratio was 2.36 (95% confidence inter- val 1.08-5.31). Classical cardiovascular risk factors did not differ among patients with and without Helicobacter pylori infection. In conclusion, patients with acute myo- cardial infarction had a significantly higher prevalence of Helicobacter pylori infection than the control popula- tion. The classical risk factors for cardiovascular diseas- es were equally distributed among patients irrespective of their Helicobacter pylori status. This work is not supported by grants R. Pellicano • V. Arena. M. Rizzetto • A. Ponzetto ( ~ ) Department of Gastroenterology,Molinette Hospital, corso Bramante n. 88, 10126 Turin, Italy M.G. Mazzarello • M. Ferrari Microbiology Laboratory, Ovada Hospital, Ovada, Italy S. Morelloni • M. Allegri Intensive Coronary Care Unit, Novi Ligure Hospital, Novi Ligure, Italy Key words Helicobacter pylori. Myocardial infarction • Ischemic heart disease • Coronary heart disease • Cardiovascular disease Introduction Acute myocardial infarction (AMI) is one of the leading causes of global mortality in countries with established market economies [1]. There are recognized classical risk factors which contribute to the pathogenesis of AMI. However, despite intensive effort, costly research, and different therapeutic approaches, mortality and morbidity due to AMI remain high. This has encouraged the search for different and "new" risk factors [2, 3]. Several lines of evidence have suggested that infections might be as- sociated with an increased risk of coronary heart disease (CHD). Moreover, when signs of systemic inflammation are present among patients with acute coronary syn- dromes the prognosis is more severe [4]. In 1994 Mendall et al. [5] reported an association be- tween Helicobacter pylori (H. pylori) infection and the risk of CHD, but a number of subsequent studies report- ed contradictory data [6-9]. Factors likely to have pro- duced these conflicting results include differences in the socioeconomic status in infancy. Ischemic heart disease and H. pylori infection both occur more commonly in people with a low socio economic status [10]. In a Welsh study, however, the adult social class remained an impor- tant risk factor for H. pylori infection after adjustment for childhood conditions [11]. Against the fact that low socio economic class per se is the key factor in the de- velopment of CHD is evidence that the Sami population in Finland has a lower mortality rate for cardiovascular diesease and a lower prevalence of It. pylori infection than the Finnish population, despite the very low socio- economic status of the Sami people [12]. Other factors which may have produced different re- sults in previous studies include the geographical area of the study, the presence of concomitant multiple infec- tions, previous antimicrobial therapy, and most notably