Atrial Fibrillation Registry for Ankle-brachial Index Prevalence Assessment: Collaborative Italian Study. (ARAPACIS)

March 8, 2016 updated by: Francesco Violi, University of Roma La Sapienza

Atrial fibrillation (AF) is the most common sustained dysrhythmia encountered in clinical practice in North America and Europe, accounting for approximately one-third of all hospitalizations for a cardiac rhythm abnormality. The presence of AF markedly increases the patient's risk for developing arterial embolism and stroke, depending on the presence of other clinical conditions, such as hypertension and diabetes. AF is associated with a fivefold increased risk for stroke, and is estimated to cause 15% of all strokes.

Patients with AF frequently have several risk factors for atherosclerosis, including hypertension, diabetes, and dyslipidemia. Accordingly, systemic signs of atherosclerosis can be detected in AF patients, and these likely accounts for an enhanced risk of coronary heart disease. In addition to cerebrovascular disease, patients with AF may suffer from coronary events including myocardial infarction (MI), but the rate of MI in AF patients seems to be variable, but often underestimated.

Moreover, coexistence of peripheral arterial disease (PAD) is a relevant clinical sign of systemic atherosclerosis.

Ankle-brachial index (ABI) is a simple, inexpensive, and non-invasive PAD measurement, even at the pre-symptomatic phase when intervention can improve prognosis and prevent or delay severe complications ABI is calculated by measuring the systolic blood pressure in the posterior tibial and/or the dorsalis pedis arteries either in both legs or 1 leg chosen at random (using a Doppler probe or alternative pulse sensor), with the lowest ankle pressure then divided by the brachial systolic blood pressure. In addition to peripheral artery disease, the ABI also is an indicator of generalized atherosclerosis because lower levels have been associated with higher rates of concomitant coronary and cerebrovascular disease, and with the presence of cardiovascular risk factors.

Two large studies in patients with AF document the existence of PAD in about 3-5% of patients. It is possible, however, that such an incidence has been underestimated as only symptomatic patients were considered as affected by PAD. As PAD is an important marker of systemic atherosclerosis, its association with AF reinforces the concept that patients with AF have systemic atherosclerosis that potentially account for coronary complications.

To date, a national registry of AF patients is not available to verify the real impact of cardiovascular events in this clinical setting.

Study Overview

Status

Completed

Conditions

Detailed Description

Study design: Prospective longitudinal study

Methods and Materials: The investigators planned to assess at baseline and at scheduled follow up visits :

  1. Ankle-Brachial Index measurement
  2. Anamnestic clinical information and Anthropometric measurements
  3. Echocardiogram (volume size), electrocardiogram (AF type)
  4. Outcome events such as nonfatal or fatal acute myocardial infarction, target lesion or vessel revascularization nonfatal or fatal ischemic stroke, transient ischemic attack, death from any cardiac or vascular cause, death from any cause Study duration: 3 years follow-up Statistical methods: The prevalence will be calculated by exact confidence intervals (Wilson method). The cumulative incidence will be calculated by the product-limit estimator of Kaplan-Meyer and presented with confidence intervals at 95%. The incidences and prevalences will be then adjusted through appropriate multivariate analysis (using the Cox proportional hazards model and logistic model) that will take into account the effect of potential confounders. Similarly, the effect-center presence will be checked and possibly removed. Secondary endpoints will be assessed by using Log-rank test method, and by the Cox model (with time-dependent effects) multivariate analysis.

Subgroups analysis will be also conducted for patients with first onset of AF or recurrent AF Sample size: The investigators plan to include in the study n = 3,000 AF patients, with competitive recruitment between centers involved in the study. The sample size was calculated assuming an expected prevalence of 19% at time zero, and in order to obtain a confidence interval 95% to prevail at time zero whose distance from the edge is less than or equal to 1.4%. This sample size yields a power greater than 99.9% for the secondary endpoint, assuming an event rate of 19% for patients with ABI <=0.9, and 10% for patients with ABI >0.9.An interim analysis showed an ABI prevalence, calculated by exact confidence intervals, of 21% in patients with AF, it is considered to interrupt the enrollment, as the observed prevalence is greater than two percentage points higher than that assumed. The sample size is amended as follows: a sample of 2027 patients leads to the expected prevalence of 21% with a confidence interval width of 3.5. This sample size has no impact on the power of the secondary objective.

Study Type

Observational

Enrollment (Actual)

2027

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Italy
      • Rome, Italy, 00161
        • Sapienza - University of Rome and SIMI
      • Rome, Italy, 00161
        • Società Italiana di Medicina Interna

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

18 years to 90 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Sampling Method

Probability Sample

Study Population

The investigators plan to include in the study n = 3,000 AF patients, with competitive recruitment between centers involved in the study. The sample size was calculated assuming an expected prevalence of 19% at time zero, and in order to obtain a confidence interval 95% to prevail at time zero whose distance from the edge is less than or equal to 1.4%. This sample size yields a power greater than 99.9% for the secondary endpoint, assuming an event rate of 19% for patients with ABI <=0.9, and 10% for patients with ABI >0.9.An interim analysis showed an ABI prevalence, calculated by exact confidence intervals, of 21% in patients with AF, it is considered to interrupt the enrollment, as the observed prevalence is greater than two percentage points higher than that assumed. The sample size is amended as follows: a sample of 2,027 patients leads to the expected prevalence of 21% with a confidence interval width of 3.5. This sample size has no impact on the power of the secondary objective.

Description

Inclusion Criteria:

  • Non-valvular atrial fibrillation (paroxysmal, persistent or permanent)
  • Genders Eligible for Study: Both
  • Ages Eligible for Study 18 years and older
  • Signed written informed consent

Exclusion Criteria:

  • Valvular AF
  • Cancer
  • Disease with life expectancy less than 3 years
  • Pregnancy
  • Hyperthyroidism

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?

Design Details

Cohorts and Interventions

Group / Cohort
Atrial fibrillation patients
Non-valvular atrial fibrillation (paroxysmal, persistent or permanent)

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
ABI PREVALENCE
Time Frame: 1 year
To estimate peripheral artery disease prevalence (defined by an Ankle-brachial index <=0.9) in AF patients.
1 year

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Vascular Events
Time Frame: 3 years
To Estimate ischemic cardiovascular and cerebro-vascular events (fatal or non-fatal ) incidence in AF patients with or without peripheral artery disease
3 years

Collaborators and Investigators

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

Sponsor

University of Roma La Sapienza

Investigators

  • Study Chair: Francesco Violi, Full Prof, Prima Clinica Medica - Sapienza University of Rome

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.

General Publications

Helpful Links

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

July 1, 2010

Primary Completion (Actual)

October 1, 2012

Study Completion (Actual)

December 1, 2014

Study Registration Dates

First Submitted

July 12, 2010

First Submitted That Met QC Criteria

July 12, 2010

First Posted (Estimate)

July 13, 2010

Study Record Updates

Last Update Posted (Estimate)

March 9, 2016

Last Update Submitted That Met QC Criteria

March 8, 2016

Last Verified

February 1, 2015

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • SIMI-ARA PACIS

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

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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