New research was presented at SCAI 2020, the virtual Society for Cardiovascular Angiography & Interventions annual meeting. The features below highlight some of the studies that emerged from the conference.
Fewer Adverse Events With Radial Vs Femoral Access in PCI for STEMI
With transradial (TR) access as a relatively novel alternative to traditional transfemoral (TF) access for vascular access in PCI but large comparisons are lacking of the efficacy, safety, and feasibility of both approaches in a standard population of patients undergoing PCI, study investigators analyzed data on major bleeding, stroke, mortality and major adverse cardiovascular and cerebrovascular events (MACCE)—a composite of an acute coronary syndrome, stroke, and mortality—across 59 studies with more than 71,000 patients. At 30-days post-PCI, odds ratios for major bleeding events, MACCE, and mortality were 0.47, 0.67, and 0.66 in the TR group when compared with the TF group, all significantly lower odds. No significant differences were observed between the groups in odds of stroke. Results were consistent across both randomized controlled trials and observational studies.
Cell Therapy Promising for Angina in Patients With Microvascular Dysfunction
Although research indicates that ischemia, angina, and other adverse outcomes can results from coronary microvascular dysfunction (CMD) in patients with nonobstructive coronary artery disease (NOCAD), specific therapies for this patient population are unavailable. With preclinical models suggesting that CD34+ cell therapy appears to augments the microvasculature and improve symptoms, exercise tolerance, and mortality in patients with refractory angina obstructive CAD, researchers conducted a trial of autologous CD34+ cell therapy in patients with NOCAD with persistent angina and invasive coronary flow reserve (CFR) or 2.5 or lower. Following a single infusion of CD34+ cells, CFR significantly increased from a mean of 2.08 at baseline to 2.68 at 6 months. Angina class was also improved at 6 months. In the 20-patient study, the number of patients in New York Heart Association class IV went from 10 to four; in class III from five to one; in class II from four to six; and in class I from one to eight. Quality of life measured on the Seattle Angina Questionnaire scale saw significant gains in physical limitation, angina stability, angina frequency, treatment satisfaction, and disease perception. No cell-related adverse events were observed.
Biodegradable Vs Durable Polymer Drug-Eluting Stents
It has been hypothesized that drug-eluting stents (DES) coated with biodegradable polymer (BP) may be safer without compromising efficacy when compared with durable polymer (DP) DES. However, data comparing BP-DES with DP-DES in high-risk patients being treated with ticagrelor are lacking. For a study, investigators conducted a pre-specified analysis of patients randomized in the TWILIGHT trial to treatment with a BP, everolimus-eluting stent (BP-EES) or a DP-DES and randomized to aspirin or placebo for 1 year following successful PCI and 3 months of ticagrelor plus aspirin. Rates of target lesion failure at 1-year were 6.0% in the BP-EES group and 4.8% in the DP-DES group. Analogous rates of definite/probable stent thrombosis and target lesion revascularization were 0.7% versus 0.5% and 5.1% versus 3.7%, respectively. Across DES groups, the effect of ticagrelor monotherapy on ischemic events was uniform. “The safety and efficacy profile of the BP-EES is comparable to that of contemporary DP-DES in high-risk patients undergoing PCI,” write the study authors. “Compared to ticagrelor plus aspirin, the effect of ticagrelor monotherapy is consistent among patients receiving BP-EES or DP-DES.”
Predicting Fractional Flow Reserve With Optical Coherence Tomography
While research indicates that optical coherence tomography (OCT) appears to allow for careful characterization of coronary plaque morphology and lumen dimensions, anatomic features that may influence coronary flow, the value of OCT in predicting fractional flow reserve (FFR) is not well established. Researchers conducted a multicenter, international, study using pooled analysis of individual patient-level data to evaluate if OCT parameters can predict FFR values and clinical outcomes in patients with negative FFR. Participants were stable or unstable patients who underwent both FFR and OCT of the same coronary lesion. Significant correlations were seen between OCT mean lumen area (MLA) and FFR values (R, 0.525) and between OCT percentage area stenosis (%AS) and FFR values (R, -0.482), whereas plaque thrombus/rupture did not differ significantly. Upon ROC analysis, an OCT-MLA less than 20 mm2 showed a good discriminative power to predict an FFR less than 0.80 and an OCT-%AS greater than 73%. When considering only proximal coronary segments, the optimal OCT cut-off values predicting an FFR less than 0.80 were MLA less than 3.1 mm2 and %AS greater than 61%.
Pros & Cons of PCI in Octogenarians With Chronic Total Occlusions
Evidence suggests increasing rates of revascularization of chronic total occlusions (CTOs), including among elderly patients choosing to undergo PCI. To assess age-related differences in outcomes of elective revascularization CTO, researchers analyzed a nationwide inpatient sample of elective admissions with a diagnosis of CTO who underwent a PCI. Patients were divided into those younger than 80 and those aged 80 and older. Compared with younger patients, those aged 80 and older had a higher prevalence of heart failure (39% vs 27%), hypertension (56% vs 46%, and chronic kidney disease (35% vs 22%). Older patients also had higher rates of postoperative cardiogenic shock (3.52% vs 2.97%), acute kidney injury (10.8% vs 8.2%), and impella use (2.58% vs 1.35%), in-hospital mortality (4% vs 1%), and non-home discharge (9% vs 5%). However, length of hospital stay and procedural costs were comparable between the age groups. Among the older group, multivariable logistic regression analysis found cardiogenic shock and acute kidney injury to be independent predictors of inpatient mortality, while heart failure and ischemic stroke were significantly associated with non-home discharge.