T he optimal treatment of patients with stable coronary artery disease (CAD) remains a matter of ongoing debate. Although revascularization provides an accepted symptomatic benefit, controversy lingers on its prognostic value when added to contemporary optimal medical care.1 Protagonists of medical therapy stress that revascularization, especially with percutaneous coronary intervention (PCI), does not reduce rates of death or myocardial infarction.2 Protagonists of mechanical therapy counter that most revascularization studies were based on anatomic guidance only, with visual estimation of stenosis severity from the coronary angiogram.3 Because ≤39% of angiographically obstructive coronary stenoses lack functional significance, no benefit should be expected from revascularizing nonischemic myocardium. 4 As a result, outcome results from existing trials are confounded by the neutral or negative effects arising from unnecessary interventions.
Background
ISIS-1 survey (conducted in 2012–2013) demonstrated a significant disconnect between guideline recommendations on invasive functional and imaging assessment of coronary stenosis severity and effective intention to adoption in patients with chronic coronary syndromes (CCS). Ever since, more evidences and new indexes/tools have become available, supposedly resulting into a simplified adoption. Therefore, six years later the second survey was repeated (ISIS-2) with the aim to evaluate a possible evolution in the intended adoption of invasive diagnostic tools.
Methods
ISIS-2 was conducted via a web-based platform from June to December 2019. Here, five complete angiograms were provided, presenting only focal intermediate stenoses. FFR and quantitative coronary angiography (QCA) values were known and kept concealed to the participants. Estimation of stenosis significance was asked for each lesion. In case of uncertainty, the most appropriate adjunctive invasive diagnostic method among QCA, intravascular ultrasound, optical coherence tomography, or invasive functional test (i.e. with FFR or a non-hyperemic index) was to be selected. Primary endpoint of the study was the rate of requested adjunctive functional or imaging assessment, as indicated by guideline recommendations. Secondary endpoint was the rate and accuracy of purely angiography-based decisions.
Results
A total of 411 participants performed 3749 lesion evaluations in ISIS-2: 2237 (60%) decisions were taken solely on angiogram and expressed no need for further evaluation with adjunctive tools. This rate of angiographic reliance was significantly reduced in ISIS-2 as compared with ISIS-1 (3139 [71%]; p<0.001). Here the decision (significant or non-significant) was discordant with the known functional significance in 870 (39%) cases, markedly less as in ISIS-1 (1459, 46%; p<0.001). In ISIS-2, participants expressed the need for either invasive functional assessment or intravascular imaging in 1110 (29%) and 379 (11%) cases, respectively. These rates were significantly higher as compared with ISIS-1 (928 [21%]; p<0.001 and 354 [8%]; p<0.001, respectively).
Conclusions
ISIS-2 survey suggests an evolving pattern over 6 years in the intention to integrate coronary angiography with invasive coronary physiology and imaging testing in patients with CCS.
Funding Acknowledgement
Type of funding source: Private company. Main funding source(s): Unrestricted grant from Abbott Medical
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