Infection and Cardiovascular Disease

To investigate the role of chronic infection as a risk factor for vascular disease in a study of Native Americans. The primary focus is on the two most common agents Chlamydia pneumoniae and cytomegalovirus with a secondary emphasis on Helicobacter pylori.

Study Overview

Detailed Description

BACKGROUND:

Recent studies have associated evidence of Chlamydia pneumoniae infection with coronary and carotid atherosclerosis and evidence of increased infection with cytomegalovirus (CMV) in patients developing restenosis or with atherosclerosis. Several other common pathogens have been less consistently associated with atherosclerosis. Altered parameters of inflammation and hemostasis have been identified as prognostic factors of myocardial infarction and have been linked as possible pathogenetic mechanisms. Recent studies have indicated that peripheral blood mononuclear cells (PBMC) from patients with coronary artery disease frequently include Chlamydia pneumoniae DNA and stimulation of PBMCs can reflect an unsuccessful host cellular immune response to CMV associated with elevated C-reactive protein (CRP).

DESIGN NARRATIVE:

The study has both a nested case-control design and a nested cohort design within the Strong Heart Study (SHS), an ongoing cohort study of 4,549 American Indians. The study utilizes previously collected specimens, baseline data, and the ultrasound measurement of carotid wall thickness (IMT) in SHS participants. Within the initial SHS cohort, 400 definite cases of incident myocardial infarction, coronary heart disease, and stroke are compared with 400 control individuals with no such diagnoses and matched for age, gender, and residence. Their prior serum specimens are analyzed for Chlamydia pneumoniae-specific IgG, IgM antibody, for cytomegalovirus-specific IgG antibody, and for C-reactive protein (CRP). In addition, assays are performed for antibodies to Helicobacter pylori, hepatitis A virus, (HAV) and herpes simplex virus (HSV) type 1 and 2. Correlations are made with baseline parameters of lipids, coagulation, and adjusted for potential confounding variables of tobacco use, pneumonia, and altered pulmonary function. An additional analysis of a subcohort, the above 400 controls, is performed looking at the outcome of their carotid IMT, a parameter of subclinical atherosclerosis, in relation to serologic results indicating a prior exposure to CMV, Chlamydia pneumoniae, and/or other pathogens approximately eight years preceding ultrasound testing. Both case-control and cohort analysis are stratified by levels of hemostasis and inflammation, including CRP, fibrinogen, Lp(a), and plasminogen-activator inhibitor-1. A separate nested substudy performed on peripheral blood mononuclear cells (PBMCs), prospectively collected from 80 cases and 80 controls, examines the host T-cell proliferative response to CMV and other pathogens in relation to disease and also searches for a chronic persistent infection with Chlamydia pneumoniae evidence by DNA detection.

The study completion date listed in this record was obtained from the "End Date" entered in the Protocol Registration and Results System (PRS) record.

Study Type

Observational

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

No older than 100 years (Child, Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

Male

Description

No eligibility criteria

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Michael Davidson, Medlantic Research Institute

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

April 1, 1999

Study Completion (Actual)

June 1, 2003

Study Registration Dates

First Submitted

May 25, 2000

First Submitted That Met QC Criteria

May 25, 2000

First Posted (Estimate)

May 26, 2000

Study Record Updates

Last Update Posted (Estimate)

February 18, 2016

Last Update Submitted That Met QC Criteria

February 17, 2016

Last Verified

January 1, 2005

More Information

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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