Procedural and Technological Innovations Facilitating Ultra-low Contrast Percutaneous Coronary Interventions.

Ultra-low-dose contrast percutaneous coronary intervention (PCI) is a valuable approach in selected complex high-risk patients with renal failure. One of the objectives of ultra-low contrast PCI is to decrease the probability of developing postprocedural contrast-induced nephropathy (CIN), which predominately affects patients with baseline renal dysfunction. CIN is associated with poor clinical outcomes and increased healthcare-related costs. Another two clinical scenarios in which reduced dependence on contrast administration by the operator may contribute to improved safety are PCI in complex, high-risk indicated patients and in shock. In this review, we discuss the procedural techniques and recent technological innovations that enable ultra-low-dose contrast PCI to be performed in the cardiac cath lab.

Coronary Physiology as Part of a State-of-the-Art Percutaneous Coronary Intervention Strategy: Lessons from SYNTAX II and Beyond.

The use of coronary physiology allows for rational decision making at the time of PCI, contributing to better patient outcomes. Yet, coronary physiology is only one aspect of optimal revascularization. State-of-the-art PCI must also consider other important aspects such as intracoronary imaging guidance and specific procedural expertise, as tested in the SYNTAX II study. In this review, we highlight the technical aspects pertaining to the use of physiology as used in that trial and offer a glimpse into the future with emerging physiologic metrics, including functional coronary angiography, which have already established themselves as useful indices to guide decision making.

Age-related changes in the coronary microcirculation influencing the diagnostic performance of invasive pressure-based indices and long-term patient prognosis.

OBJECTIVES: Investigate age-related changes in coronary microvascular function, its effect on hyperemic and non-hyperemic indices of stenosis relevance, and its prognostic implications. BACKGROUND: Evidence assessing the effect of age on fractional flow reserve (FFR), resting mean distal intracoronary pressure/mean aortic pressure (Pd/Pa), and microcirculatory function remains scarce. METHODS: This is a post hoc study of a large prospective international registry (NCT03690713) including 1134 patients (1326 vessels) with coronary stenoses interrogated with pressure and flow guidewires. Age-dependent correlations with functional indices were analyzed. Prevalences of FFR, resting Pd/Pa, and coronary flow reserve (CFR) classification agreement were assessed. At 5 years follow-up, the relation between resting Pd/Pa, CFR, and their age-dependent implications on FFR-guided percutaneous coronary intervention (PCI) deferral (deferred if FFR > 0.80) were investigated using vessel-oriented composite outcomes (VOCO) composed of death, myocardial infarction, and repeated revascularization. RESULTS: Age correlated positively with FFR (r = 0.08, 95% confidence interval [CI]: 0.03 to 0.13, p = 0.005), but not with resting Pd/Pa (r = -0.03, 95% CI:-0.09 to 0.02, p = 0.242). CFR correlated negatively with age (r = -0.15, 95% CI: -0.21 to -0.10, p < 0.001) due to a significant decrease in maximal hyperemic flow in older patients. Patients over 60 years of age with FFR-guided deferred-PCI abnormal resting Pd/Pa or abnormal CFR had increased risk of VOCO (hazard ratio [HR]: 2.10, 95% CI: 1.15 to 4.36, p = 0.048; HR: 2.46, 95% CI:1.23 to 4.96, p = 0.011; respectively). CONLUSIONS: Aging is associated with decrease in microcirculatory vasodilation, as assessed with adenosine-based methods like CFR. In patients older than 60 years in whom PCI is deferred according to FFR > 0.80, CFR and resting Pd/Pa have an incremental value in predicting future vessel-oriented patient outcomes.