Concordance between vessel-specific and vascular territory coronary functional assessment: A comparison of quantitative flow ratio and myocardial perfusion scintigraphy.

BACKGROUND: Quantitative flow ratio (QFR) and myocardial perfusion scintigraphy (MPS) are utilized for assessing coronary artery disease (CAD) significance. We aimed to analyze their concordance and prognostic impact. AIMS: We aimed to analyze the concordance between QFR and MPS and their risk stratification. METHODS: Patients with invasive coronary angiography and MPS were categorized as concordant if QFR ≤ 0.80 and summed difference score (SDS) ≥ 4 or if QFR > 0.80 and SDS < 4; otherwise, they were discordant. Concordance was classified by coronary territory involvement: total (three territories), partial (two territories), poor (one territory), and total discordance (zero territories). Leaman score assessed coronary atherosclerotic burden. RESULTS: 2010 coronary territories (670 patients) underwent joint QFR and MPS analysis. MPS area under the curve for QFR ≤ 0.80 was 0.637. Concordance rates were total (52.5%), partial (29.1%), poor (15.8%), and total discordance (2.6%). Most concordance occurred in patients without significant CAD or with single-vessel disease (89.5%), particularly without MPS perfusion defects (91.5%). Leaman score (odds ratio [OR]: 0.839, 95% confidence interval [CI]: 0.805-0.875, p < 0.001) and MPS perfusion defect (summed stress score [SSS] ≥ 4) (OR: 0.355, 95% CI: 0.211-0.596, p < 0.001) were independent predictors for discordance. After 1400 days, no significant difference in death/myocardial infarction was observed based on MPS assessment, but Leaman score, functional Leaman score, and average QFR identified higher risk patients. CONCLUSIONS: MPS showed good overall accuracy in assessing QFR significance but substantial discordance existed. Predictors for discordance included higher atherosclerotic burden and MPS perfusion defects (SSS ≥ 4). Leaman score, QFR-based functional Leaman score, and average QFR provided better risk stratification for all-cause death and myocardial infarction than MPS.

Impact of plaque characteristics on the degree of functional stenosis.

Coronary CT angiography (CCTA) is mainly regarded as a gatekeeper for invasive coronary angiography, in face of its widely recognized value to noninvasively rule out significant coronary stenosis. Nevertheless, it is also increasingly recognized that this noninvasive modality can depict several atherosclerotic plaque features and quantify total coronary plaque burden. This opens a new field for cardiac CT, since these atherosclerotic features beyond stenosis severity have been correlated with the degree of functional significance, and are the focus of the present manuscript. Although recently acknowledged and documented in CCTA studies, the relation between plaque burden and functional significance has been previously described using several intracoronary imaging modalities, which are also reviewed in the manuscript, to help put in perspective the relation between anatomy and function in coronary artery disease.

Longest available clinical outcomes after drug-eluting stent implantation for unprotected left main coronary artery disease: the DELFT (Drug Eluting stent for LeFT main) Registry.

OBJECTIVES: The purpose of this study was to investigate the long-term safety and efficacy of percutaneous coronary intervention (PCI) with drug-eluting stent (DES) implantation for unprotected left main coronary artery (ULMCA) disease. BACKGROUND: Long-term clinical outcomes after DES implantation for ULMCA disease have not yet been ascertained. METHODS: From April 2002 to April 2004, 358 consecutive patients who underwent PCI with DES implantation for de novo lesions on ULMCA were retrospectively selected and analyzed in 7 European and U.S. tertiary care centers. No patients were excluded from the analysis, and all patients had a minimum follow-up of 3 years. RESULTS: Technical success rate was 100%. Procedural success rate was 89.6%. After 3 years, major adverse cardiovascular events (MACE)-free survival in the whole population was 73.5%. According to the Academic Research Consortium definitions, cardiac death occurred in 9.2% of patients, and reinfarction, target lesion revascularization (TLR), and target vessel revascularization (TVR) occurred in 8.6%, 5.8%, and 14.2% of patients, respectively. Definite stent thrombosis occurred in 2 patients (specifically at 0 and 439 days). In elective patients, the 3-year MACE-free survival was 74.2%, with mortality, reinfarction, TLR, and TVR rates of 6.2%, 8.3%, 6.6%, and 16%, respectively. In the emergent group the 3-year MACE-free survival was 68.2%, with mortality, reinfarction, TLR, and TVR rates of 21.4%, 10%, 2.8%, and 7.1%, respectively. CONCLUSIONS: Routine DES implantation in ULMCA disease seems encouraging, with favorable long-term clinical results.