Angela Ferrara

Intracoronary Adenosine: Dose-Response Relationship With Hyperemia.

OBJECTIVES The present study sought to establish the dosage of intracoronary (IC) adenosine associated with minimal side effects and above which no further increase in flow can be expected. BACKGROUND Despite the widespread adoption of IC adenosine in clinical practice, no wide-ranging, dose-response study has been conducted. A recurring debate still exists regarding its optimal dose. METHODS In 30 patients, Doppler-derived flow velocity measurements were obtained in 10 right coronary arteries (RCAs) and 20 left coronary arteries (LCAs) free of stenoses >20% in diameter. Flow velocity was measured at baseline and after 8 ml bolus administrations of arterial blood, saline, contrast medium, and 9 escalating doses of adenosine (4 to 500 μg). The hyperemic value was expressed in percent of the maximum flow velocity reached in a given artery (Q/Qmax, %). RESULTS Q/Qmax did not increase significantly beyond dosages of 60 μg for the RCA and 160 μg for LCA. Heart rate did not change, whereas mean arterial blood pressure decreased by a maximum of 7% (p < 0.05) after bolus injections of IC adenosine. The incidence of transient A-V blocks was 40% after injection of 100 μg in the RCA and was 15% after injection of 200 μg in the LCA. The duration of the plateau reached 12 ± 13 s after injection of 100 μg in the RCA and 21 ± 6 s after the injection of 200 μg in the LCA. A progressive prolongation of the time needed to return to baseline was observed. Hyperemic response after injection of 8 ml of contrast medium reached 65 ± 36% of that achieved after injection of 200 μg of adenosine. CONCLUSIONS This wide-ranging, dose-response study indicates that an IC adenosine bolus injection of 100 μg in the RCA and 200 μg in the LCA induces maximum hyperemia while being associated with minimal side effects.

Significance of Intermediate Values of Fractional Flow Reserve in Patients With Coronary Artery Disease.

Background— The fractional flow reserve (FFR) value of 0.75 has been validated against ischemic testing, whereas the FFR value of 0.80 has been widely accepted to guide clinical decision making. However, revascularization when FFR is 0.76 to 0.80, within the so-called gray zone, is still debatable. Methods and Results— From February 1997 to June 2013, all patients with single-segment disease and an FFR value within the gray zone or within the 2 neighboring FFR strata (0.70–0.75 and 0.81–0.85) were included. Study end points consisted of major adverse cardiovascular events (death, myocardial infarction, and any revascularization) up to 5 years. Of 17 380 FFR measurements, 1459 patients were included. Of them, 449 patients were treated with revascularization and 1010 patients were treated with medical therapy. In the gray zone, the major adverse cardiovascular events rate was similar (37 [13.9%] versus 21 [11.2%], respectively; P=0.3) between medical therapy and revascularization, whereas a strong trend toward a higher rate of death or myocardial infarction (25 [9.4] versus 9 [4.8], P=0.06) and overall death (20 [7.5] versus 6 [3.2], P=0.059) was observed in the medical therapy group. Among medical therapy patients, a significant step-up increase in major adverse cardiovascular events rate was observed across the 3 FFR strata, especially with proximal lesion location. In revascularization patients, the major adverse cardiovascular events rate was not different across the 3 FFR strata. Conclusions— FFR in and around the gray zone bears a major prognostic value, especially in proximal lesions. These data confirm that FFR⩽0.80 is valid to guide clinical decision making.

Fractional Flow Reserve–Guided Revascularization in Patients With Aortic Stenosis

Fractional flow reserve (FFR) has never been investigated in patients with aortic stenosis (AS). From 2002 to 2010, we identified 106 patients with AS and coronary artery disease with at least one intermediate lesion treated according to FFR guidance. We matched 212 contemporary control patients with AS in which revascularization was decided on angiography only. More patients in the FFR-guided group underwent percutaneous coronary intervention (24% vs 13%; p = 0.019), whereas there was a trend toward less coronary artery bypass grafting (CABG) performed. After FFR, the number of diseased vessels was downgraded within the FFR-guided group (from 1.85 ± 0.97 to 1.48 ± 1; p <0.01) and compared with the angio-guided group (1.48 ± 1 vs 1.8 ± 0.97; p <0.01). Less aortic valve replacement was reported in the FFR-guided group (46% vs 57%; p = 0.056). In patients who underwent CABG, less venous conduits (0.5 ± 0.69 vs 0.73 ± 0.76; p = 0.05) and anastomoses (0.61 ± 0.85 vs 0.94 ± 1; p = 0.032) were necessary in the FFR-guided group. Up to 5 years, we found no difference in major adverse cardiac events (38% vs 39%; p = 0.98), overall death (32% vs 31%; p = 0.68), nonfatal myocardial infarction (2% vs 2%; p = 0.79), and revascularization (8% vs 7%; p = 0.76) between the 2 groups. In conclusion, FFR guidance impacts the management of selected patients with moderate or severe AS and coronary artery disease by resulting into deferral of aortic valve replacement, more patients treated with percutaneous coronary intervention, and in patients treated with CABG, into less venous grafts and anastomoses without increasing adverse event rates up to 5 years.

Saline-Induced Coronary Hyperemia: Mechanisms and Effects on Left Ventricular Function

Background— During thermodilution-based assessment of volumetric coronary blood flow, we observed that intracoronary infusion of saline increased coronary flow. This study aims to quantify the extent and unravel the mechanisms of saline-induced hyperemia. Methods and Results— Thirty-three patients were studied; in 24 patients, intracoronary Doppler flow velocity measurements were performed at rest, after intracoronary adenosine, and during increasing infusion rates of saline at room temperature through a dedicated catheter with 4 lateral side holes. In 9 patients, global longitudinal strain and flow propagation velocity were assessed by transthoracic echocardiography during a prolonged intracoronary saline infusion. Taking adenosine-induced maximal hyperemia as reference, intracoronary infusion of saline at rates of 5, 10, 15, and 20 mL/min induced 6%, 46%, 111%, and 112% of maximal hyperemia, respectively. There was a close agreement of maximal saline- and adenosine-induced coronary flow reserve (intraclass correlation coefficient, 0.922; P<0.001). The same infusion rates given through 1 end hole (n=6) or in the contralateral artery (n=6) did not induce a significant increase in flow velocity. Intracoronary saline given on top of an intravenous infusion of adenosine did not further increase flow. Intracoronary saline infusion did not affect blood pressure, systolic, or diastolic left ventricular function. Heart rate decreased by 15% during saline infusion (P=0.021). Conclusions— Intracoronary infusion of saline at room temperature through a dedicated catheter for coronary thermodilution induces steady-state maximal hyperemia at a flow rate ≥15 mL/min. These findings open new possibilities to measure maximal absolute coronary blood flow and minimal microcirculatory resistance.

First prospective multicenter experience with the 7 French Glidesheath slender for complex transradial coronary interventions

To assess the feasibility and safety of the 7 French (Fr) Glidesheath Slender for complex transradial (TR) percutaneous coronary interventions (PCI).

iFR-FFR comparison in daily practice: a single-center, prospective, online assessment.

Aims To compare the performance of instantaneous wave-free ratio (iFR) with fractional flow reserve (FFR) in a real-life, prospective, single-center, and independent study. Methods and results Fifty-four patients were included and 89 angiographic intermediate lesions underwent functional evaluation with both iFR and FFR. FFR was used as the gold standard, and the patients having FFR values 0.80 or less only underwent percutaneous coronary intervention. Linear regression demonstrated close agreement between the two techniques (R = 0.83, P < 0.0001). Receiver operator characteristic analysis confirmed the strong correlation, with an area under the curve approximately equal to unity. iFR detected ischemia with a sensitivity and specificity of 100 and 87%, respectively, thus revealing a positive predictive value of 78% and a negative predictive value of 100%. In addition, according to FFR assessment, percutaneous coronary intervention was performed on 39 lesions (43.8%) in 27 patients (50%), whereas positive iFR values were found in 52 lesions (+14.6% compared with FFR). At clinical follow-up (ranging from 6 to 16 months), all patients remained asymptomatic and none of them experienced major adverse cardiovascular events. Conclusions In this independent, online, comparison of iFR-FFR values in patients with angiographic intermediate lesions, results are consistent with those derived from previous offline controlled trials, and support the correlation between iFR and FFR in daily clinical practice.

Single String Technique for Coronary Bifurcation Stenting: Detailed Technical Evaluation and Feasibility Analysis

OBJECTIVES The study aimed to evaluate the adequacy and feasibility of the single string bifurcation stenting technique. BACKGROUND Double-stent techniques may be required for complex bifurcations. Currently applied methods all have their morphological or structural limitations with respect to wall coverage, multiple strut layers, and apposition rate. METHODS Single string is a novel method in which, first, the side branch (SB) stent is deployed with a single stent cell protruding into the main branch (MB). Second, the MB stent is deployed across this protruding stent cell. The procedure is completed by final kissing balloon dilation. The single string technique was first tested in vitro (n = 20) and next applied in patients (n = 11) with complex bifurcation stenoses. RESULTS All procedures were performed successfully, crossing a single stent cell in 100%. Procedure duration was 23.0 ± 7.9 min, and the fluoroscopy time was 9.4 ± 3.5 min. The results were evaluated by optical coherence tomography, showing fully apposed struts in 83.0 ± 9.2% in the bifurcation area. Residual area obstruction in the MB was 6.4 ± 5.6% and 25.0 ± 16.9% in the SB, as evaluated by micro computed tomography. All the human cases were performed successfully with excellent angiographic results: the residual area stenosis was 27 ± 8% and 29 ± 10% in the MB and in the SB, respectively, by 3-dimensional quantitative coronary angiography. No relevant periprocedural enzyme increase was observed. During follow-up (6 ± 4 months), no adverse clinical events (death, myocardial infarction, target vessel revascularization) were noted. CONCLUSIONS The single string technique for complex bifurcation dilation was shown to be adequate in vitro and feasible in humans, with favorable results in terms of stent overlap, malapposition rate, and low residual obstruction in both the MB and SB.

The present day potential role of fractional flow reserve–guided coronary artery bypass graft surgery

The favorable impact of fractional flow reserve measurements on the decision-making and overall outcomes of percutaneous coronary artery intervention is well established. However, the clinical application of fractional flow reserve in surgical revascularizations is still debated. The purpose of this article is to provide a comprehensive review on the current potential role of fractional flow reserve guidance in coronary artery bypass grafting.

Visual and Quantitative Assessment of Coronary Stenoses at Angiography Versus Fractional Flow Reserve

Background— The correlation between angiographic assessment of coronary stenoses and fractional flow reserve (FFR) is weak. Whether and how risk factors impact the diagnostic accuracy of angiography is unknown. We sought to evaluate the diagnostic accuracy of angiography by visual estimate and by quantitative coronary angiography when compared with FFR and evaluate the influence of risk factors (RF) on this accuracy. Methods and Results— In 1382 coronary stenoses (1104 patients), percent diameter stenosis by visual estimation (DSVE) and by quantitative coronary angiography (DSQCA) was compared with FFR. Patients were divided into 4 subgroups, according to the presence of RFs, and the relationship between DSVE, DSQCA, and FFR was analyzed. Overall, DSVE was significantly higher than DSQCA (P<0.0001); nonetheless, when examined by strata of DS, DSVE was significantly smaller than DSQCA in mild stenoses, although the reverse held true for severe stenoses. Compared with FFR, a large scatter was observed for both DSVE and DSQCA. When using a dichotomous FFR value of 0.80, C statistic was significantly higher for DSVE than for DSQCA (0.712 versus 0.640, respectively; P<0.001). C statistics for DSVE decreased progressively as RFs accumulated (0.776 for ⩽1 RF, 0.750 for 2 RFs, 0.713 for 3 RFs and 0.627 for ≥4 RFs; P=0.0053). In addition, in diabetics, the relationship between FFR and angiographic indices was particularly weak (C statistics: 0.524 for DSVE and 0.511 for DSQCA). Conclusions— Overall, DSVE has a better diagnostic accuracy than DSQCA to predict the functional significance of coronary stenosis. The predictive accuracy of angiography is moderate in patients with ⩽1 RFs, but weakens as RFs accumulate, especially in diabetics.

Clinical outcomes of secondary prevention strategies for young patients with cryptogenic stroke and patent foramen ovale

Abstract Background The aim of this study was to compare the immediate and long-term clinical outcomes of medical therapy and percutaneous patent foramen ovale (PFO) closure as secondary prevention strategies in patients younger than 55 years of age presenting with cryptogenic stroke and PFO. Methods Between January 2006 and April 2015, all patients with the diagnosis of cryptogenic stroke and PFO were analysed and prospectively followed. Stroke was confirmed in 159 out of 309 patients (51%). In the remaining cases, other neurological conditions were found and therefore excluded from further analysis. Patients received PFO closure or medical therapy on the basis of a pre-specified algorithm. Primary outcome was the assessment of recurrent ischaemic events at follow-up. Results Percutaneous PFO closure was performed in 77 patients (48%) and 82 (52%) were treated medically. Mean follow-up was 51.6 ± 34.8 months. Two ischaemic strokes occurred in the medical group only (2.4% vs 0%; P = 0.16) and no complications related to the invasive procedure were observed. Conclusions The diagnosis of stroke in patients with PFO could be confirmed in 50% of cases only, underlining the importance of a multidisciplinary evaluation of these patients. A very low ischaemic recurrence rate was observed in the medical therapy group, suggesting that a personalized treatment based on a prespecified diagnostic algorithm yields good clinical results irrespective of the treatment modality. Given the low number of recurrences, larger cohorts may be needed to prove significant differences.