Global longitudinal strain for prediction of mortality in ST-segment elevation myocardial infarction and aortic stenosis patients: two sides of the same coin.

OBJECTIVE: Global longitudinal strain (GLS) predicts major adverse events in ST-segment elevation myocardial infarction (STEMI) and aortic stenosis (AS). Different cut-off values and different end-points have been proposed for prognostic stratification. We aimed to verify whether a single GLS cut-off value can be used to identify increased risk of all-cause death in STEMI and AS. PATIENTS AND METHODS: One-hundred- seventeen successfully treated first STEMI (age 63.8±12.5 yrs, 70% men) and 64 AS (age 80.3±6.9 yrs, 44% men) patients, undergoing echocardiography before discharge and before AS treatment, respectively, were retrospectively analyzed. GLS was analyzed, together with pulmonary artery systolic pressure (PASP), Killip class and Genereux stage. End-point was all-cause death at 6-month follow-up. RESULTS: All-cause death occurred in 4 (3.4%) STEMI and 5 (7.8%) AS patients (p=ns). AS patients who died had GLS similar to died STEMI patients (9.7±2.1 vs. 11.3±1.7, p=ns). GLS cut-off ≤12% predicted death with 89% sensitivity and 70% specificity (AUC 0.84, p=0.001): STEMI and AS patients with GLS ≤12% had worse survival than STEMI and AS patients with GLS >12% (log-rank p=0.001). At multivariate Cox regression analysis, lower GLS values independently predicted death (HR 0.667, 95% CI 0.451-0.986, p=0.042), and the prediction model was improved when GLS was added to old age, significant comorbidities, PASP and Killip/Genereux stage (χ2 6.691 vs. 1.364, p=0.010). CONCLUSIONS: Died patients with STEMI and AS show similar values of GLS. A unique cut-off value of GLS can reliably be used to stratify the risk of all-cause death at 6-month follow-up in both two clinical settings.

Coronary plaque instability assessed by positron emission tomography and optical coherence tomography.

BACKGROUND: Non-ST-elevation myocardial infarction (NSTEMI) and unstable angina (UA) are caused often by destabilization of non-flow limiting inflamed coronary artery plaques. 18F-fluorodeoxyglucose (FDG) uptake with positron emission tomography/computed tomography (PET/CT) reveals plaque inflammation, while intracoronary optical coherence tomography (OCT) reliably identifies morphological features of coronary instability, such as plaque rupture or erosion. We aimed to prospectively compare these two innovative biotechnologies in the characterization of coronary artery inflammation, which has never been attempted before. METHODS: OCT and FDG PET/CT were performed in 18 patients with single vessel coronary artery disease, treated by percutaneous coronary intervention (PCI) with stent implantation, divided into 2 groups: NSTEMI/UA (n = 10) and stable angina (n = 8) patients. RESULTS: Plaque rupture/erosion recurred more frequently [100% vs 25%, p = 0.001] and FDG uptake was greater [TBR median 1.50 vs 0.87, p = 0.004] in NSTEMI/UA than stable angina patients. FDG uptake resulted greater in patients with than without plaque rupture/erosion [1.2 (0.86-1.96) vs 0.87 (0.66-1.07), p = 0.013]. Among NSTEMI/UA patients, no significant difference in FDG uptake was found between ruptured and eroded plaques. The highest FDG uptake values were found in ruptured plaques, belonging to patients with NSTEMI/UA. OCT and PET/CT agreed in 72% of patients [p = 0.018]: 100% of patients with plaque rupture/erosion and increased FDG uptake had NSTEMI/UA. CONCLUSION: For the first time, we demonstrated that the correspondence between increased FDG uptake with PET/CT and morphology of coronary plaque instability at OCT is high.

Ticagrelor and preconditioning in patients with stable coronary artery disease (TAPER-S): a randomized pilot clinical trial.

BACKGROUND: Ticagrelor is a reversibly binding, direct-acting, oral, P2Y12 antagonist used for the prevention of atherothrombotic events in patients with coronary artery disease (CAD). Ticagrelor blocks adenosine reuptake through the inhibition of equilibrative nucleoside transporter 1 (ENT-1) on erythrocytes and platelets, thereby facilitating adenosine-induced physiological responses such as an increase in coronary blood flow velocity. Meanwhile, adenosine plays an important role in triggering ischemic preconditioning through the activation of the A1 receptor. Therefore, an increase in ticagrelor-enhanced adenosine bioavailability may confer beneficial effects through mechanisms related to preconditioning activation and improvement of coronary microvascular dysfunction. METHODS: To determine whether ticagrelor can trigger ischemic preconditioning and influence microvascular function, we designed this prospective, open-label, pilot study that enrolled patients with stable multivessel CAD requiring staged, fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI). Participants will be randomized in 1:1 ratios either to ticagrelor (loading dose (LD) 180 mg, maintenance dose (MD) 90 mg bid) or to clopidogrel (LD 600 mg, MD 75 mg) from 3 to 1 days before the scheduled PCI. The PCI operators will be blinded to the randomization arm. The primary endpoint is the delta (difference) between ST segment elevations (in millimeters, mm) as assessed by intracoronary electrocardiogram (ECG) during the two-step sequential coronary balloon inflation in the culprit vessel. Secondary endpoints are 1) changes in coronary flow reserve (CFR), index of microvascular resistance (IMR), and FFR measured in the culprit vessel and reference vessel at the end of PCI, and 2) angina score during inflations. This study started in 2018 with the aim of enrolling 100 patients. Based on the rate of negative FFR up to 30% and a drop-out rate up to 10%, we expect to detect an absolute difference of 4 mm among the study arms in the mean change of ST elevation following repeated balloon inflations. All study procedures were reviewed and approved by the Ethical Committee of the Catholic University of Sacred Heart. DISCUSSION: Ticagrelor might improve ischemia tolerance and microvascular function compared to clopidogrel, and these effects might translate to better long-term clinical outcomes. TRIAL REGISTRATION: EudraCT No. 2016-004746-28. No. NCT02701140.  TRIAL STATUS: Information provided in this manuscript refers to the definitive version (n. 3.0) of the study protocol, dated 31 October 2017, and includes all protocol amendments. Recruitment started on 18 September 2018 and is currently ongoing. The enrollment is expected to be completed by the end of 2019. TRIAL SPONSOR: Fondazione Policlinico Universitario A. Gemelli - Roma, Polo di Scienze Cardiovascolari e Toraciche, Largo Agostino Gemelli 8, 00168 Rome, Italy.

Radial artery intima-media ratio predicts presence of coronary thin-cap fibroatheroma: a frequency domain-optical coherence tomography study.

BACKGROUND: Peripheral arterial disease is a risk factor for cardiac mortality but pathophysiologic mechanisms linking atherosclerosis of peripheral arteries with coronary events in the single patient have not been established. METHOD AND RESULTS: We evaluated by frequency-domain optical coherence tomography (FD-OCT) the possible association between culprit coronary plaque characteristics and proximal radial artery features in a cohort of 51 patients symptomatic coronary artery disease undergoing coronary procedures by transradial route. FD-OCT coronary artery analysis included assessment of TCFA and thrombus. FD-OCT radial artery analysis included intimal thickness index (ITI: intimal area/medial area), intima-media ratio (IMR: the maximum intimal thickness/medial thickness), and percentage of luminal narrowing [%LN: (intimal area+medial area)/external elastic membrane area × 100]. Coronary TCFA and thrombus were detected in 19 (37%) and 7 (14%) patients, respectively. TCFA was significantly associated with higher values of radial artery ITI (0.35 vs. 0.26, p=0.02) and IMR (0.45 vs. 0.32, p=0.03), but not with %LN. In contrast, coronary thrombus was only associated with higher %LN (26.7 vs. 22.8, p=0.02). Multivariate logistic regression analysis identified proximal radial artery IMR (OR 16.3, 95% CI 1.1 to 245.1) as an independent predictor of TCFA. CONCLUSIONS: In patients with symptomatic coronary atherosclerosis, vessel wall modifications at the level of the proximal radial artery are associated with adverse coronary features like TCFA and thrombus.

EuroSCORE as predictor of in-hospital mortality after percutaneous coronary intervention.

OBJECTIVE: To date, no common risk stratification system is available to predict the risk of surgical or percutaneous myocardial revascularisation in patients with coronary artery disease (CAD). Thus, we sought to assess the European System for Cardiac Operative Risk Evaluation (EuroSCORE) validity to predict in-hospital mortality after percutaneous coronary intervention (PCI). DESIGN, SETTING AND PARTICIPANTS: EuroSCORE was prospectively and systematically assessed in 1173 consecutive patients undergoing PCI in a high-volume single centre between April 2005 and October 2006. MAIN OUTCOME MEASURE: The receiver-operating characteristics (ROC) curve was used to describe performance and accuracy of the EuroSCORE risk model for the prediction of in-hospital mortality after PCI. RESULTS: The EuroSCORE model demonstrated an overall relation between EuroSCORE rank and the incidence of in-hospital mortality, showing consistency in predicting patient risk across many subgroups and levels of global risk. At multivariable logistic regression analysis the EuroSCORE value was an independent in-hospital mortality predictor (p = 0.002) together with left main disease (p = 0.005), procedural urgency (p = 0.001), ACC/AHA C type lesion (p = 0.02) and PCI failure (p = 0.01). The area under the ROC curve for the EuroSCORE system was 0.91 (95% CI 0.86 to 0.97), indicating a good ability of the model to discriminate patients at risk of dying during the index hospitalisation. CONCLUSION: The EuroSCORE risk model, already extensively validated for the prediction of early mortality following open-heart surgery, can also be efficiently utilised in the setting of PCI. The introduction of the EuroSCORE assessment in patients with documented CAD may help to improve the revascularisation strategy decision-making process.

Major improvement of percutaneous cardiovascular procedure outcomes with radial artery catheterisation: results from the PREVAIL study.

OBJECTIVE: To obtain a "snapshot" view of access-specific percutaneous cardiovascular procedures outcomes in the real world. DESIGN: Multicentre, prospective study performed over a 30-day period. SETTING: Nine hospitals with invasive cardiology facilities, reflecting the contemporary state of healthcare. PATIENTS: Unselected consecutive sample of patients undergoing any percutaneous cardiovascular procedure requiring an arterial access. INTERVENTIONS: Percutaneous cardiovascular procedures by radial or femoral access MAIN OUTCOME MEASURES: The primary outcome was the combined incidence of in-hospital (a) major and minor haemorrhages; (b) peri-procedural stroke; and (c) entry-site vascular complications. The secondary outcome was the combined incidence of in-hospital death and myocardial infarction/reinfarction. For analysis purposes, outcomes were allocated to arterial access-determined study arms on an intention-to treat basis. Multivariable analysis adjusted using propensity score was performed to correct for selection bias related to arterial site. RESULTS: A total of 1052 patients were enrolled: 509 underwent radial access and 543 femoral access. In both groups, 40% underwent a coronary angioplasty. Relative to femoral access, radial access was associated with a lower incidence both of primary (4.2% vs 1.96%, p = 0.03, respectively) and secondary endpoints (3.1% vs 0.6%, p = 0.005, respectively). Multivariate analysis, adjusted for procedural and clinical confounders, confirmed that intention-to-access via the radial route was significantly and independently associated with a decreased risk both of primary (OR 0.37, 95% CI 0.16 to 0.84) and secondary endpoints (OR 0.14, 95% CI 0.03 to 0.62). CONCLUSIONS: Our study indicates strikingly better outcomes of percutaneous cardiovascular procedures with radial access versus femoral access in contemporary, real-world clinical settings.

Sirolimus, Tacrolimus and Zotarolimus eluting stents to treat bifurcated lesions: a 7-month clinical outcome comparison.

AIM: Drug eluting stents (DES) have been shown to reduce restenosis compared with bare metal stents in bifurcated lesions. The aim of this study was to evaluate the long-term clinical outcomes of patients with bifurcated lesions treated by 3 different DES. METHODS: Consecutive patients with symptomatic coronary artery disease on one bifurcated lesion with SB>2.25 mm (on visual estimation) undergoing at the Department of Cardiology of the Catholic University of Rome, Italy were screened. Patients treated with Sirolimus-eluting stent (Cypher Select; SES Group), Tacrolimus-eluting stent (Taxus-Libertè; TA Group) and Zotarolimus-eluting stent (Endeavor Driver; ZOT Group) were enrolled in the study. Clinical and angiographic characteristics of all patients were prospectively recorded. Major adverse clinical events (MACE), including death, acute myocardial infarction (MI) or target lesion revascularization (TVR) by either percutaneous coronary intervention (PCI) or coronary surgery were recorded during the follow-up. Incidence of definite or probable stent thrombosis was calculated according to the ARC criteria. RESULTS: Two hundred and forty-one consecutive patients were enrolled (89 Group CY, 98 Group TA and 54 Group EN). Length of follow-up was 235+/-60 days. Baseline clinical and angiographic characteristic were similar across the groups. The adopted technique for stent implantation was provisional stenting (73.4%), T-stenting technique (7%), crush (7%) and V-stenting (2.6%). The rate of patients finally treated with two stents was similar among groups. The cumulative rate of MACE (9% SES, 12% TA, 11% ZOT: P=0.7) and of TVR (2% SES, 9% TA, 7% ZOT) was similar among groups. No definite stent thrombosis was observed during follow-up, while 1 probable stent thrombosis was observed in TA group. CONCLUSION: The clinical outcome of bifurcated lesions using DES and mainly a technique of single stent implantation is good. In the present observational study, clinical adverse events did not differ in patients with bifurcated lesions treated by Cypher, Taxus or Endeavor stent implantation.

Filter no reflow during percutaneous coronary interventions using the Filterwire distal protection device.

BACKGROUND: Distal protection devices are increasingly used to prevent embolization during percutaneous coronary interventions (PCI) in saphenous vein grafts (SVG) and native coronary arteries (NV). During interventions with the Filterwire device we have observed reduced flow that is reversible following removal of the filter (filter no reflow, FNR), which might be erroneously interpreted as true no reflow and might be associated with reduced capture efficiency of the basket. METHODS: We analyzed the incidence of FNR in 58 patients (60 lesions) at high risk of embolization undergoing PCI of either a SVG or a NV using the Filterwire (Boston Scientific, Natick, MA). Qualitative and quantitative angiographic analysis was performed, and the volume of collected debris was estimated using a photographic technique. RESULTS: In our population, about 1/3 of the cases showed FNR, which was associated with angiographically visible filling defects within the basket, indicating macroembolism. However some patients (especially those undergoing vein graft interventions) showed filling defects without FNR, and some others FNR without filling defects. Thus we tried to understand the predictors of FNR: FNR was associated with higher amount of collected debris (36.97 +/- 42.98 mm(3) vs. 11.31 +/- 18.47 mm(3), p = 0.005), was neither prevented by abciximab, nor predicted by high thrombotic burden, increasing stent volume or need for predilatation. When patient with and without angiographically evident macroembolisation were separately analyzed, a linear correlation of FNR with the quantity of debris was only apparent in the macroembolization group. CONCLUSIONS: Interventionalists should be aware of the "Filter No Reflow", a common but reversible angiographic complication when the Filterwire device is used. Reduced flow seen during these procedures should be treated conservatively. Mechanical obstruction of the filter, but also other mechanisms (pharmacologically active debris? platelet aggregates?) play a role in this phenomenon.

Increased mortality after coronary stenting in patients treated with clopidogrel without loading dose. Evidence from a meta-analysis.

AIM: Clopidogrel is an established alternative to ticlopidine in addition to aspirin after coronary stenting because of its hematologic safety, but its efficacy in comparison to ticlopidine is debated. We thus systematically reviewed randomized trials comparing clopidogrel vs ticlopidine after coronary stenting. METHODS: Medline (1/1986-10/2003), BioMed Central, Central, Current Contents, LILACS and mRCT were searched. Fixed-effect relative risks (RR [95% CI]) were computed, and the primary end-point was death. Heterogeneity tests and subgroup analyses were performed according to loading vs non-loading clopidogrel scheme. RESULTS: Five trials were retrieved (2 962 patients, average follow-up 7.4 months). In 3 studies both clopidogrel and ticlopidine were started with a loading dose, in 1 trial clopidogrel was administered without loading, and in 1 trial clopidogrel could be administered with or without loading. Overall analysis (p for heterogeneity=0.12) showed a non-significant trend toward increased mortality in patients treated with clopidogrel (38/1 649 [2.3%]) vs ticlopidine (22/1 313 [1.7%], RR=1.64 [0.94-2.86], p=0.080). After stratification, clopidogrel with loading was associated with non-significantly lower mortality rates than ticlopidine (9/959 [0.9%] vs 13/798 [1.6%], RR=0.68 [0.29-1.63], p=0.39). Instead, clopidogrel without any loading yielded a highly significantly 3-fold increased risk of death than ticlopidine (29/690 [4.2%] vs 9/515 [1.7%], RR=2.9 [1.45-6.1], p=0.0029). Similar results were obtained for the rate of death or non-fatal myocardial infarction. CONCLUSION: This meta-analysis suggests that clopidogrel treatment including a loading regimen is equivalent or may even be superior to ticlopidine after coronary stenting. However, current evidence shows conversely that clopidogrel therapy in the absence of a loading dose is associated with a significantly higher risk of death or myocardial infarction.

Ticlopidine and aspirin fail to suppress the increased platelet aggregability that follows percutaneous coronary interventions.

Previous studies indicate that percutaneous transluminal coronary angioplasty (PTCA) is associated with platelet activation. It is not well-established whether enhanced platelet aggregability after PTCA is prevented by the association of ticlopidine with aspirin. The aim of this study was to evaluate whole blood platelet aggregability before and after elective PTCA in patients with chronic stable angina receiving ticlopidine and aspirin. We studied 16 patients referred for elective PTCA, treated for > or = 72 hours with oral aspirin and ticlopidine (group 1), and 10 patients referred for diagnostic coronary angiography, treated with oral aspirin alone (group 2). An intravenous bolus of heparin was administered at the start of PTCA. In both groups, platelet aggregability was assessed at baseline and 24 hours after the procedure, using the PFA 100(R) system. This method measures the time required for flowing whole blood to occlude a collagen and adenosine diphosphate (ADP)-coated ring, shorter times indicating greater aggregability. In both groups, platelet aggregability after the procedure was significantly increased compared with baseline: 104+/-30 seconds before versus 88+/-24 seconds at 24 hours in group 1 (p=0.03) and 84+/-16 seconds before versus 69+/-14 seconds at 24 hours in group 2 (p=0.004). Group 1 patients, compared with group 2, showed a trend toward reduced aggregability at baseline (p=0.06) and significantly lower aggregability 24 hours after the procedure (p=0.03). Ticlopidine and aspirin reduce whole-blood platelet aggregability compared with aspirin alone but fail to suppress the increased aggregability that occurs 24 hours after PTCA.

Midterm endothelial function and remodeling of radial artery grafts anastomosed to the aorta.

BACKGROUND: The purpose of this study was to elucidate the midterm endothelium-dependent vasodilatory capacity of radial artery grafts anastomosed to the aorta, as well as their morphometric evolution with the time. METHODS: Five years after surgery we evaluated the response of aorta-anastomosed radial artery grafts to the endovascular infusion of acetylcholine in 11 of the first 61 patients operated on at our institution, and we compared it to the response with that of internal thoracic artery grafts. Moreover, the first 20 patients who had a perfect radial artery graft on angiography at 1 year were restudied at 5 years and subjected to a comparative analysis of the diameters of the radial artery graft and the grafted coronary arteries. RESULTS: At midterm angiography, dilation of the 2 types of grafts was similar in response to acetylcholine administration (radial artery, from 2.61 +/- 0.39 to 2. 90 +/- 0.34 mm; internal thoracic artery, from 2.68 +/- 0.21 to 2.93 +/- 0.27 mm; P =.01 for both). The diameters of aorta-anastomosed radial artery grafts and grafted coronary arteries increased between both 1 and 5 years according to angiographic studies (radial artery grafts, from 2.08 +/- 0.45 to 2.54 +/- 0.53 mm; grafted coronary arteries, from 1.92 +/- 0.47 to 2.18 +/- 0.41 mm; P <.001 for both), but the increase was greater for the radial artery grafts (P <.001). CONCLUSIONS: Aorta-anastomosed radial artery grafts maintain an appreciable capacity for endothelium-dependent vasodilatation 5 years after implantation and undergo a progressive increase in luminal diameter with time. These observations contradict the presumed tendency for progressive fibrous intimal hyperplasia to develop in radial artery grafts.

Relationship between myocardial 123I-metaiodobenzylguanidine scintigraphic uptake and heart rate variability in patients with syndrome X.

BACKGROUND: We have recently demonstrated a striking impairment in cardiac uptake of 123I-metaiodobenzylguanidine (MIBG) in most patients with syndrome X. In this study we investigated the relationship between cardiac MIBG defects and cardiac autonomic activity in these patients. METHODS: MIBG myocardial scintigraphy and time-domain and frequency-domain heart rate variability (HRV) were compared in 11 syndrome X patients and 10 healthy controls. Cardiac MIBG uptake was assessed by the heart/mediastinum ratio and a cardiac MIBG uptake defect score (higher values = lower uptake). RESULTS: The heart/mediastinum ratio was lower (1.71 +/- 0.6 vs 2.19 +/- 0.3, p = 0.03) and MIBG uptake score higher (37.1 +/- 32 vs 4.0 +/- 2.5, p = 0.005) in syndrome X patients, whereas average HRV values did not differ between the two groups. However, while there were no correlations between MIBG uptake and HRV in controls, in syndrome X patients both the heart/mediastinum ratio and MIBG uptake score correlated significantly with two HRV parameters, specific for vagal activity: the square root of the mean squared differences of consecutive RR intervals (r = 0.73, p = 0.01, and r = -0.67, p = 0.02, respectively), and high frequency (r = 0.64, p = 0.03, and r = -0.74, p = 0.009, respectively). CONCLUSIONS; In patients with syndrome X, the impairment in cardiac MIBG uptake was associated with a reduction in HRV indexes mainly reflecting vagal modulation of sinus node, thus suggesting that a predominance of cardiac adrenergic activity may be present in those with abnormal cardiac MIBG scintigraphy.

Reversible left anterior descending artery spasm, prolonged cardiac arrest and left main thrombosis during a PTCA attempt of the circumflex artery.

The authors report a case of percutaneous transluminal coronary angioplasty of the circumflex artery complicated by occlusion of the non-diseased left anterior descending artery by spasm. During advanced cardiac life support, required for the subsequent cardiac arrest, intra-coronary nitrates and calcium antagonists were administered. After 45 minutes, the spasm resolved, but N probably as a result of prolonged blood stasis N a thrombus appeared in the left main artery. While attempting to stent the left main, the thrombus was mechanically dislodged, leaving the epicardial coronary tree free, with a good flow.

[Remodelling of the radial artery graft 5 years after aortocoronary bypass intervention]. / Rimodellamento dei graft in arteria radiale a cinque anni dall'intervento di bypass aortocoronarico.

BACKGROUND: The radial artery (RA) is being employed as coronary artery bypass graft with good results, but when it is proximally anastomosed to the ascending aorta, undergoes substantial hemodynamic changes which could lead to significant graft intimal hyperplasia. The aim of this study was to investigate the evolution of RA graft morphology over time. METHODS: We studied 20 patients with a perfectly patent RA graft at both 1 and 5 year angiography after coronary artery bypass graft. RESULTS: Both RA graft and grafted coronary artery diameters, assessed by quantitative coronary angiography, significantly increased at 5 years, in comparison to 1 year angiography (2.08 +/- 0.45 vs 2.54 +/- 0.53 mm, +22%, p < 0.001 and 1.92 +/- 0.47 vs 2.18 +/- 0.41 mm, +13.3%, p < 0.001, respectively). CONCLUSIONS: Hemodynamic changes following RA employment for coronary artery bypass graft stimulate a remodeling of RA graft itself and of the grafted coronary arteries. The progressive increase of diameters observed in RA grafts strongly argues against the development of flow-limiting graft intimal hyperplasia when RA is proximally anastomosed to the ascending aorta. Moreover, grafted coronary artery dilation suggests that hemorrheologic changes following coronary artery bypass graft could play a major role in the development of RA remodeling over time.

[The radial artery in coronary surgery: the midterm clinical and angiographic results and the variation in vasoreactivity over time]. / L'arteria radiale in chirurgia coronarica: risultati clinici ed angiografici a medio termine e variazione della vasoreattività nel tempo.

OBJECTIVE: To evaluate the mid-term angiographic results of radial artery grafts used for myocardial revascularization. METHODS: The first 68 consecutive surviving patients who received a radial artery graft proximally anastomosed to the aorta at our institution were restudied in a five-year follow-up (mean 59 +/- 6.5 months); 48 of these patients had already undergone an early angiographic examination. The response of the radial artery to the endovascular infusion of serotonin was evaluated one and five years after surgery and the mid-term status of the radial artery grafts was correlated with the degree of stenosis of the target vessel and with the Ca(++)-channel-blocker therapy. RESULTS: The patency and perfect patency rates of the radial artery five years after the operation were 91.9 and 87.0% respectively. All radial artery grafts that were patent early after surgery remained patent at mid-term follow-up and in seven patients early parietal irregularities disappeared after five years. The early propensity to graft spasm after serotonin challenge decreased markedly at mid-term follow-up. The continued use of Ca(++)-antagonists after the first postoperative year did not affect the status of the radial artery graft, whereas the severity of target-vessel stenosis markedly influenced the angiographic results. CONCLUSIONS: The mid-term angiographic results of RA grafts used for myocardial revascularization are excellent. A correct surgical indication is essential, whereas continued therapy with Ca(++)-antagonists after the first year does not influence the mid-term angiographic results.

Midterm clinical and angiographic results of radial artery grafts used for myocardial revascularization.

OBJECTIVE: To evaluate the midterm angiographic results of the use of radial artery grafts for myocardial revascularization. METHODS: The first 68 consecutive surviving patients who received a radial artery graft proximally anastomosed to the aorta at our institution were studied again at 5 years (mean 59 +/- 6.5 months) of follow-up; 48 of these patients had previously undergone an early angiographic examination. The response of the radial artery to the endovascular infusion of serotonin was evaluated 1 and 5 years after the operation, and the midterm status of the radial artery graft was correlated with the degree of preoperative stenosis of the target vessel and with calcium-channel blocker therapy. RESULTS: The patency and perfect patency rates of the radial artery grafts 5 years after the operation were 91.9% and 87.0%, respectively. All radial artery grafts that were patent early after the operation remained patent at midterm follow-up, and early parietal irregularities in 7 patients were seen to have disappeared after 5 years. The early propensity toward graft spasm after serotonin challenge was markedly decreased at midterm follow-up. The continued use of calcium-channel antagonists after the first postoperative year did not influence the radial artery graft status, whereas the preoperative severity of the target-vessel stenosis markedly influenced the angiographic results. CONCLUSIONS: The midterm angiographic results of radial artery grafts used for myocardial revascularization are excellent. The correct surgical indication is essential. Continued therapy with calcium-channel antagonists after the first year does not influence the midterm angiographic results.

Non-invasive evaluation of mammary artery flow reserve and adequacy to increased myocardial oxygen demand.

OBJECTIVE: To evaluate the flow reserve and adequacy to meet myocardial requests in stress conditions of mammary artery-left anterior descending (IMA-LAD) grafts using a non-invasive method. METHODS: Patients (20) with angiographic evidence of normofunctioning left IMA-LAD grafts were submitted to dypiridamole Tl201 myocardial scintigraphy and concomitant transthoracic echo-doppler evaluation of the IMA flow at a mean interval of 32.5 months after surgery. RESULTS: Under basal conditions, the mean peak and end flow velocities in systole were 0.39 and 0.06 m/s, respectively. In diastole, the mean peak and end flow velocities were 0.27 and 0.02 m/s and mean tele-diastolic flow velocity was 0.14 m/s, with a mean systolic/diastolic ratio of 1.51. After dypiridamole infusion, mean systolic velocities were 0.47 (peak) and 0.23 (end) m/s, respectively + 20 and + 283%, whereas mean diastolic velocities were 0.56 (peak) and 0.06 (end) m/s, +107 and +200%, respectively. Mean tele-diastolic flow velocity increased to 0.32 m/s (+128%) and the systolic-diastolic index changed to 0.85. In all cases no significant scintigraphic evidence of induced ischemia was demonstrated in the LAD region. CONCLUSIONS: Transthoracic echo-doppler evaluation combined with Tl201 myocardial scintigraphy is a useful tool for the assessment of IMA flow reserve and adequacy to stress conditions. In the late postoperative period, the IMA shows the possibility of increasing the flow velocity, almost 2-fold; the increase in flow is prevalently diastolic and leads to a complete reversal of the physiological systolic/diastolic flow ratio. The flow reserve of IMA is always able to meet the augmented myocardial oxygen demand after dypiridamole infusion.

Steal phenomenon from mammary side branches: when does it occur?

BACKGROUND: The hemodynamic significance of patent mammary graft side branches is still controversial. This study was designed to evaluate the potential for flow steal of patent mammary side branches in different hemodynamic conditions. METHODS: Echo-Doppler measurement of mammary graft flow was performed at rest and after dipyridamole-induced coronary vasodilatation in 10 patients with angiographic demonstration of evident mammary graft side branches (study group) and in 10 matched control patients (control group). Concomitant thallium-201 myocardial scintigraphy was performed to assess the adequacy of mammary flow to the myocardial oxygen demand. Patients of the study group were also submitted to flow evaluation in condition of selective muscular or combined systemic and coronary relaxation. RESULTS: No difference in mammary flow and adequacy to myocardial oxygen demand was detected between patients of the study and control groups both at rest and after dipyridamole infusion. In patients with patent side branches the systolic-to-diastolic flow ratio was maintained in case of combined coronary and peripheral vasodilatation, whereas selective muscular relaxation led to an increase in the systolic and a reduction in the diastolic flow. CONCLUSIONS: Flow steal from patent mammary graft side branches is possible only in case of selective muscular vasodilatation. As this situation is unlikely to occur in the clinical setting, the potential for flow steal of mammary side branches in cardiac surgery patients seems to be minimal.