VITAL-AF Trial - Cardionerds Twitter Journal Club

CardioNerds Journal Club is a monthly forum for CardioNerds to discuss and breakdown recent publications on twitter and are produced with a corresponding infographic and detailed blog post. For more information, check out the CardioNerds Journal Club Page. This Journal Club focuses on the VITAL-AF Trial.

Table of contents for the VITAL-AF Trial summary:

Visual abstract
Summary
References
Credits
Twitter Archive

March 2, 2022

Screening for Atrial Fibrillation in Older Adults at Primary Care Visits: VITAL-AF Randomized Controlled Trial

Steven A. Lubitz, Steven J. Atlas, Jeffrey M. Ashburner, Ana T. Trisini Lipsanopoulos, Leila H. Borowsky, Wyliena Guan, Shaan Khurshid, Patrick T. Ellinor, Yuchiao Chang, David D. McManus and Daniel E. Singer

https://www-ahajournals-org.proxy.library.upenn.edu/doi/10.1161/CIRCULATIONAHA.121.057014

Relevant Literature – VITAL-AF Trial

Relevant Guidelines -VITAL-AF Trial

European Society of Cardiology recommends opportunistic screening with either pulse palpation or ECG rhythm strip at clinic visits in patients at least 65 years of age (2020).

US Preventive Services Task Force has stated that evidence is insufficient to recommend screening using ECGs (2020).

National Heart Foundation of Australia and the Cardiac Society of Australia and New Zealand indicate opportunistic annual screening for AF in general practice in patients aged 65 years or more is easily accomplished by pulse palpation, followed by an ECG (if irregular), or by an ECG rhythm strip using a handheld ECG (2018).

Study Rationale – VITAL-AF Trial

Prospective studies on AF screening showed that it’s feasible to have point-of-care screening, but all of which were uncontrolled studies. Furthermore, the main hypothesis of earlier diagnosis of AF was towards stroke prevention in those who are confirmed to have AF and are candidates for anticoagulation. Thus, the study accordingly focuses on primary screening with single-lead ECG at primary care practices.

Objective

The study aimed to assess whether routine screening of older adults (age over 65 years) using single-lead ECGs is more effective in identifying patients with AF than usual care in a contemporary primary care practice setting.

Trial

Pragmatic cluster randomized controlled trial

Participating clinics were the unit of randomization
1. Cluster randomization at the practice level was used to facilitate the implementation of the screening intervention and to minimize contamination in control patients

Intervention

Randomly assigned 1 of the 2 optimal paired groups to the screening intervention

Consenting patients placed their fingers on a single-lead AliveCor KardiaMobile ECG device (AliveCor Inc, Mountain View, CA) affixed to an iPad (Apple Inc, Cupertino, CA) using the KardiaAI version 1 algorithm to conduct AF screening

Screening result categories included: “Possible AF,” “Normal,” “Unclassified,” “No Analysis (Unreadable),” and “Patient Declined”

All subsequent clinical management was determined by primary care clinicians, including follow-up 12-lead ECGs

Independent cardiologists reviewed all tracings within 7 days and notified primary care clinicians if a prespecified actionable rhythm was identified.

Enrollment Criteria

Outcomes

Statistical Analysis

Primary analyses were conducted using the intention-to-treat sample, and sensitivity analyses were conducted using the per-protocol and as-treated samples

For the primary outcome of AF incidence, unadjusted and adjusted generalized linear regression models that included established AF risk factors were used to compare the 2 groups
Exploratory analyses were used to investigate the heterogeneity of treatment effect by prespecified factors (age, sex, heart rate, predicted risk of AF, implanted cardiac devices, history of 12-lead ECG use, and number of primary care clinician visits in the previous year)
The likelihood of incident AF detection on the same day of a primary care clinic visit in a study practice and the proportion of individuals with new oral anticoagulant prescriptions were compared between the 2 groups using a Poisson regression model with the generalized estimating equations approach to account for the repeated measures from the same individuals
Statistical significance was defined as a 2-tailed P value ≤0.05, and all analyses were conducted using SAS version 9.4
Study had 80% power to detect a 0.48% increase in AF incidence rate (1.60% to 2.08%) when 85% of the screening group subjects were screened

Sample size: 30,715 patients

Participant Characteristics:

Overall, patient features in the screening and control arms were well balanced
59.7% female (screening) vs 58.1% female (control)
82.4% white (screening) vs 82.5% white (control)

No significant differences in pre-existing comorbidities or predicted 5-year AF risk

Outcomes

Primary Outcomes:

Primary outcome of newly diagnosed AF occurred in 264 (1.72%) individuals in the screening arm versus 243 (1.59%) in the control arm at 1 year (RD, 0.13% [95% CI, –0.16 to 0.42]; P=0.38

Secondary Outcomes:

The difference in newly diagnosed AF between the screening period and the previous year was marginally greater in the screening versus control group (0.32% versus –0.12%; RD, 0.43% [95% CI, –0.01 to 0.84]). This effect of screening was primarily observed in patients 85 years and older

Likelihood of being diagnosed with new AF at a primary care visit in a study practice was greater in the screening versus the control group (0.24% [92 events/38382 encounters] versus 0.15% [62 events/40003 encounters]; RD, 0.08% [95% CI, 0.02 to 0.15])
Proportion of individuals with newly diagnosed AF who were initiated on oral anticoagulants was not different in the screening (n=194, 73.5%) and control (n=172, 70.8%) arms (RD, 2.7% [95% CI, –5.5 to 10.4]

Likelihood of being diagnosed with new AF at a primary care visit in a study practice was greater in the screening versus the control group (0.24% [92 events/38382 encounters] versus 0.15% [62 events/40003 encounters]; RD, 0.08% [95% CI, 0.02 to 0.15])
Proportion of individuals with newly diagnosed AF who were initiated on oral anticoagulants was not different in the screening (n=194, 73.5%) and control (n=172, 70.8%) arms (RD, 2.7% [95% CI, –5.5 to 10.4]

Conclusions

Screening for AF using a single-lead ECG at primary care visits did not affect new AF diagnoses among all individuals aged 65 years or older compared with usual care.
Point-of-care screening for AF may be clinically effective among those with advanced age, but this secondary result warrants further evaluation.

Limitations & Considerations

It’s possible that differences in AF incidences between the screening and control arms biased the primary overall screening effect towards null or non-significant difference between the screening arm and control, as a difference-in- differences analysis suggested a positive effect of screening on new AF diagnoses in the screening arm.
Racial diversity of patient population was limited, preventing race/ethnicity stratified results