Optimising physiological endpoints of percutaneous coronary intervention

US Volume Flow Assessment to Optimize Angioplasty of Dysfunctional Dialysis Access: The VOLA-II Multicenter Study

Background Digital subtraction angiography and thrill palpation demonstrate limitations when used to assess the outcomes of angioplasty in autologous arteriovenous fistulas (AVFs). Purpose To investigate a new functional quantifiable index of successful angioplasty for failing AVFs using intraprocedural percutaneous US volume flow (VF) measurements. Materials and Methods This prospective, multicenter, single-arm, cohort clinical trial included consecutive patients with indications for fluoroscopically guided balloon angioplasty due to AVF dysfunction between June 2020 and May 2022. Intraprocedural VF measurements were obtained before the procedure and after balloon dilation using transcutaneous duplex US. The primary end points were the quantification of VF-guided angioplasty outcomes and assessment of the association between postprocedural VF and freedom from target lesion reintervention (TLR) due to recurrence of access failure. Cox multivariate regression analysis was performed to identify predictors of TLR-free survival, which was estimated using Kaplan-Meier methods. Receiver operating characteristic curve analysis was used to determine the optimal cutoff VF value. Results In total, 100 participants (mean age, 67 years ± 12 [SD]; 84 male) were evaluated. The rate of freedom from TLR was 73% at 6 months. The mean pre- and postintervention VF values were 353 mL/min ± 199 and 1045 mL/min ± 413, respectively. Higher VF at completion of angioplasty (hazard ratio, 0.89 per 100 mL/min [95% CI: 0.82, 0.98]; P = .01) and forearm versus upper arm AVF (hazard ratio, 0.51 [95% CI: 0.27, 0.95]; P = .03) were independent predictors of increased freedom from TLR. A postprocedural VF of 720 mL/min (P < .001) was identified as the optimal cutoff point for predicting increased fistula freedom from reintervention and freedom of restenosis for radiocephalic AVFs, compared with an optimal cutoff point of 1120 mL/min (P = .03) for upper arm AVFs. Conclusion Intraprocedural VF measurement is a quantifiable functional index and postprocedural predictor of outcomes following angioplasty for failing dialysis AVFs. ClinicalTrials.gov identifier: NCT04694287 © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Prince et al this issue.

Comparison of Angiographic Success and Clinical Outcomes Based on Different Percutaneous Coronary Intervention Techniques

Introduction Primary percutaneous coronary intervention (PCI) is the standard treatment for patients with ST-segment elevation myocardial infarction (STEMI). Various PCI techniques exist, including balloon angioplasty, bare-metal stents (BMS), drug-eluting stents (DES), thrombus aspiration, direct stenting, rotational atherectomy (Rotablation), and cutting balloon angioplasty. Specific approaches for patients with STEMI and multivessel coronary artery disease may involve: 1) culprit vessel-only (CVO) primary PCI, 2) primary PCI followed by multivessel intervention of additional noninfarct lesions at the same procedure, or 3) CVO primary PCI followed by staged PCI of noninfarct lesions later during the index hospitalization or after discharge. However, their impact on angiographic success and clinical outcomes remains unclear. Methodology A retrospective study (n=90) evaluated the effectiveness of various PCI techniques during primary PCI. Data included demographics, clinical profiles, PCI strategies, and outcomes. Techniques such as thrombus aspiration, direct stenting, balloon angioplasty, and DES deployment were assessed. Descriptive statistics and chi-square tests were employed, with logistic regression for adjustment. Results The comparison of angiographic success and clinical outcomes based on different PCI strategies during primary PCI (n=90) revealed distinct differences. Successful procedures were associated with lower mean values for age (56.00 vs. 60.20), hypertension (165.50 vs. 170.30), weight (74.00 vs. 77.50), BMI, 26.80 vs. 28.70, KILLIP class (1.30 vs. 1.50), ejection fraction (45.80 vs. 47.90), creatinine (0.95 vs. 1.00), creatinine clearance (83.50 vs. 86.70), pulse rate (84.00 vs. 87.50), oxygen saturation (95.80 vs. 94.50), and blood sugar (170.00 vs. 182.00). Risk factors like hypertension (mean = 1.40 vs. 1.60), diabetes (mean = 1.60 vs. 1.70), and hyperlipidemia (mean = 1.85 vs. 1.95) also showed differences between successful and failed procedures. Significant variations were observed across PCI strategies for outcomes including angina within 30 days (Chi square = 18.75, p < 0.001), cerebrovascular accident (CVA, Chi square = 15.42, p = 0.001), acute left ventricular failure (LVF, Chi square = 12.67, p = 0.005), and cardiogenic shock (Chi square = 8.93, p = 0.029). Conclusion Patient demographics and clinical profiles influence PCI success. Techniques such as thrombus aspiration, direct stenting, balloon angioplasty, and DES have varied impacts on clinical outcomes. While conventional balloon angioplasty remains a viable option, newer techniques such as DES and mechanical thrombectomy demonstrate superior angiographic success rates and improved clinical outcomes, particularly in complex lesion subsets. However, the selection of PCI technique should be guided by careful consideration of patient-specific factors, lesion characteristics, and procedural feasibility.

Future of invasive and non-invasive hemodynamic assessment for coronary artery disease management

Coronary artery disease represents a global health challenge. Accurate diagnosis and evaluation of hemodynamic parameters are crucial for optimizing patient management and outcomes. Nowadays a wide range of both non-invasive and invasive methods are available to assess the hemodynamic impact of both epicardial coronary stenosis and vasomotor disorders. In fact, over the years, important developments have reshaped the nature of both invasive and non-invasive diagnostic techniques, and the future holds promises for further innovation and integration. Non-invasive techniques have progressively evolved and currently a broad spectrum of methods are available, from cardiac magnetic resonance imaging with pharmacological stress and coronary computed tomography (CT) to the newer application of FFR-CT and perfusion CT. Invasive methods, on the contrary, have developed to a full-physiology approach, able not only to identify functionally significant lesions but also to evaluate microcirculation and vasospastic disease. The aim of this review is to summarize the current state-of-the-art of invasive and non-invasive hemodynamic assessment for CAD management.

Physiology and Intravascular Imaging Coregistration-Best of all Worlds?

Percutaneous coronary intervention is increasingly guided by coronary physiology and optimized using intravascular imaging. Pressure-based measurements determine the significance of a stenosis using hyperemic or nonhyperemic pressure ratios (eg, the instantaneous wave-free ratio). Intravascular ultrasound and optical coherence tomography provide cross-sectional and longitudinal detail regarding plaque composition and vessel characteristics. These facilitate lesion preparation and optimization of stent sizing and positioning. This review explores the evidence-base and practical aspects of coregistering pressure gradient assessment and intravascular imaging with angiography. We then discuss gaps in the evidence and what is needed to help integrate these techniques into clinical practice.

In search for "healthy" landing zones for coronary stent placement: are the largest intrasegmental lumens adequate?

Background

Coronary lesions are supposed to be enclosed between proximal and distal reference segments (RSs), the sites with the largest lumens within the same vessel segment. Finding "healthy" landing zones has been fundamental for efficient stent implantation. Consequently, our study aimed to determine, using optical coherence tomography (OCT), to what degree RSs conform to this concept.

Methods

Sixty-seven patients with a mean age of 63.5 years underwent culprit lesion stenting due to acute myocardial infarction (MI) (Group 1) or stable angina (Group 2). OCT was performed with commercially available equipment; all evaluations were made at RSs and minimal lumens.

Results

Normal vessel wall was infrequent (~10%) at RSs. Acceptable external elastic 220°) occurred in 55% to 67% and in 28% to 31% of RSs, respectively. Tissue composition at RSs was similar in both study groups except for a greater accumulation of thin-cap fibroatheromas (TCFA) in acute MI (29% in Group 1 vs. 9% in Group 2, P=0.035). Flow deterioration after stenting was associated with TCFA clusters extending from culprit main bodies into proximal RSs (P=0.008).

Conclusions

Optimal landing zones for stent placement should frequently be searched for beyond the culprit lesion segments although utilizing the largest intrasegmental lumens does not seem to cause immediate harm. However, TCFA at the landings should definitely be avoided.

Physiology and Intravascular Imaging Coregistration-Best of all Worlds?

Percutaneous coronary intervention is increasingly guided by coronary physiology and optimized using intravascular imaging. Pressure-based measurements determine the significance of a stenosis using hyperemic or nonhyperemic pressure ratios (eg, the instantaneous wave-free ratio). Intravascular ultrasound and optical coherence tomography provide cross-sectional and longitudinal detail regarding plaque composition and vessel characteristics. These facilitate lesion preparation and optimization of stent sizing and positioning. This review explores the evidence-base and practical aspects of coregistering pressure gradient assessment and intravascular imaging with angiography. We then discuss gaps in the evidence and what is needed to help integrate these techniques into clinical practice.

Revascularization in stable coronary artery disease

Management of stable coronary artery disease (CAD) centers on medication to prevent myocardial infarction and death. Many anti-anginal medications also have benefit for reducing symptoms, and have been proven to be effective against placebo control. Before effective preventive medications were available, patients with stable CAD often underwent revascularization with coronary artery bypass grafting (CABG) or percutaneous coronary intervention (PCI), on the plausible assumption that these procedures would prevent adverse events and reduce symptoms. However, recent randomized controlled trials have cast doubt on these assumptions.Considering results from the recent ISCHEMIA trial, we discuss the evidence base that underpins revascularization for stable CAD in contemporary practice. We also focus on patient groups at high risk of myocardial infarction and death, for whom revascularization is often recommended. We outline the areas of uncertainty, unanswered research questions, and key areas of potential miscommunication in doctor-patient consultations.

Coronary Flow Variations Following Percutaneous Coronary Intervention Affect Diastolic Nonhyperemic Pressure Ratios More Than the Whole Cycle Ratios

Background Post-percutaneous coronary intervention (PCI) fractional flow reserve ≥0.90 is an accepted marker of procedural success, and a cutoff of ≥0.95 has recently been proposed for post-PCI instantaneous wave-free ratio. However, stability of nonhyperemic pressure ratios (NHPRs) post-PCI is not well characterized, and transient reactive submaximal hyperemia post-PCI may affect their precision. We performed this study to assess stability and reproducibility of NHPRs post-PCI. Methods and Results Fifty-seven patients (age, 63.77±10.67 years; men, 71%) underwent hemodynamic assessment immediately post-PCI and then after a recovery period of 10, 20, and 30 minutes and repeated at 3 months. Manual offline analysis was performed to derive resting and hyperemic pressure indexes (Pd/Pa resting pressure gradient, mathematically derived instantaneous wave-free ratio, resting full cycle ratio, and fractional flow reserve) and microcirculatory resistances (basal microvascular resistance and index of microvascular resistance). Transient submaximal hyperemia occurring post-PCI was demonstrated by longer thermodilution time at 30 minutes compared with immediately post-PCI; mean difference of thermodilution time was 0.17 seconds (95% CI, 0.07-0.26 seconds; P=0.04). Basal microcirculatory resistance was also higher at 30 minutes than immediately post-PCI; mean difference of basal microvascular resistance was 10.89 mm Hg.s (95% CI, 2.25-19.52 mm Hg.s; P=0.04). Despite this, group analysis confirmed no significant differences in the values of resting whole cycle pressure ratios (Pd/Pa and resting full cycle ratio) as well as diastolic pressure ratios (diastolic pressure ratio and mathematically derived instantaneous wave-free ratio). Whole cardiac cycle NHPRs demonstrated the best overall stability post-PCI, and 1 in 5 repeated diastolic NHPRs crossed the clinical decision threshold. Conclusions Whole cycle NHPRs demonstrate better reproducibility and clinical precision post-PCI than diastolic NHPRs, possibly because of less perturbation from predominantly diastolic reactive hyperemia and left ventricular stunning. Registration URL: https://clinicaltrials.gov/ct2/show/NCT03502083; Unique identifier: NCT03502083 and URL: https://clinicaltrials.gov/ct2/show/NCT03076476; Unique identifier: NCT03076476.