A smartphone application using the phone's camera function performed better than traditional physical examination to assess blood flow in a wrist artery for patients undergoing coronary angiography, according to a randomised trial in Canada.
These findings highlight the potential of smartphone applications to help physicians make decisions at the bedside. "Because of the widespread availability of smartphones, they are being used increasingly as point-of-care diagnostics in clinical settings with minimal or no cost," says Dr Benjamin Hibbert of the University of Ottawa Heart Institute, Ottawa, Ontario.
"For example, built-in cameras with dedicated software or photodiode sensors using infrared light-emitting diodes have the potential to render smartphones into functional plethysmographs (instruments that measure changes in blood flow)."
The researchers compared the use of a heart-rate monitoring application (the Instant Heart Rate application version 4.5.0 on an iPhone 4S) with the modified Allen test, which measures blood flow in the radial and ulnar arteries of the wrist, one of which is used to access the heart for coronary angiography. A total of 438 participants were split into two groups; one group was assessed using the app and the other was assessed using a gold-standard traditional physical examination (known as the Allen test). The smartphone app had a diagnostic accuracy of 94% compared with 84% using the traditional method.
"The current report highlights that a smartphone application can outperform the current standard of care and provide incremental diagnostic yield in clinical practice," writes Hibbert, with colleagues. "However, while they aren't designed as medical devices – when smartphones and apps begin to be used clinically – it is important that they are evaluated in the same rigorous manner by which we assess all therapies and diagnostic tests," says lead author Dr Pietro Di Santo. "When we designed the iRadial study we wanted to hold the technology to the highest scientific standards to make sure the data supporting its use was as robust as possible."
"Although this application is not certified at present for use in health care by any regulatory body, our study highlights the potential for smartphone-based diagnostics to aid in clinical decision-making at the patient's bedside," concludes Hibbert.
The health care profession and regulatory agencies should proactively address the challenges associated with bringing mobile health (mHealth) solutions into practice to maximize their benefits, writes Dr Kumanan Wilson, of The Ottawa Hospital and the University of Ottawa, in a related commentary.
"Referred to as a new industrial revolution, the impact of digital technologies will be both disruptive and transformative," he writes. "The continued maturation of technologies, such as artificial intelligence, virtual reality and blockchain, will further expand the possibilities for mHealth in both diagnosis and treatment in health care."
Abstract
Background: Radial artery access is commonly performed for coronary angiography and invasive hemodynamic monitoring. Despite limitations in diagnostic accuracy, the modified Allen test (manual occlusion of radial and ulnar arteries followed by release of the latter and assessment of palmar blush) is used routinely to evaluate the collateral circulation to the hand and, therefore, to determine patient eligibility for radial artery access. We sought to evaluate whether a smartphone application may provide a superior alternative to the modified Allen test.
Methods: We compared the modified Allen test with a smartphone heart rate–monitoring application (photoplethysmography readings detected using a smartphone camera lens placed on the patient’s index finger) in patients undergoing a planned cardiac catheterization. Test order was randomly assigned in a 1:1 fashion. All patients then underwent conventional plethysmography of the index finger, followed by Doppler ultrasonography of the radial and ulnar arteries (the diagnostic standard). The primary outcome was diagnostic accuracy of the heart rate–monitoring application.
Results: Among 438 patients who were included in the study, we found that the heart rate–monitoring application had a superior diagnostic accuracy compared with the modified Allen test (91.8% v. 81.7%, p = 0.002), attributable to its greater specificity (93.0% v. 82.8%, p = 0.001). We also found that this application had greater diagnostic accuracy for assessment of radial or ulnar artery patency in the ipsilateral and contralateral wrist (94.0% v. 84.0%, p < 0.001).
Interpretation: A smartphone application used at the bedside was diagnostically superior to traditional physical examination for confirming ulnar patency before radial artery access. This study highlights the potential for smartphone-based diagnostics to aid in clinical decision-making at the patient’s bedside.
Authors
Pietro Di Santo, David T Harnett, Trevor Simard, F Daniel Ramirez, Ali Pourdjabbar, Altayyeb Yousef, Robert Moreland, Jordan Bernick, George Wells, Alexander Dick, Michel Le May, Marino Labinaz, Derek So, Pouya Motazedian, Richard G. Jung, Jaya Chandrasekhar, Roxana Mehran, Aun-Yeong Chong, Benjamin Hibbert
[link url="https://www.sciencedaily.com/releases/2018/04/180403085054.htm"]Canadian Medical Association material[/link]
[link url="http://www.cmaj.ca/content/190/13/E380"]Canadian Medical Association Journal abstract[/link]
[link url="http://www.cmaj.ca/content/190/13/E378"]Canadian Medical Association Journal commentary[/link]