Performance of the XLIMUS sirolimus-eluting coronary stent in very complex lesions.

AIM: In an attempt to improve the stent's safety and effectiveness, development of drug-eluting stents (DES) continues, with new materials and geometry. XLIMUS (CARDIONOVUM GmbH, Germany) is a new DES with the following potential advantages 1) excellent stent platform; 2) biodegradable polymer; and 3) potent antiproliferative drug (sirolimus). METHODS: In this pilot study, we assessed the safety and efficacy of percutaneous coronary interventions (PCI) using the new XLIMUS DES in patients undergoing elective PCI in native coronary vessels for complex de novo lesions, including: 1) severe calcification; 2) severe tortuosity; and 3) chronic total occlusion (CTO). RESULTS: A total of 53 consecutive patients with 59 lesions were analyzed. Severe calcifications occurred in 21% of patients; severe tortuosity in 45%, and CTO in 34%. The device success was obtained in 52 (98%) patients and in 58 (98%) lesions. Globally, the XLIMUS DES was successfully implanted by conventional PCI techniques on the first try with a single guidewire in 48/53 (90.5%) patients and 54/59 (91.5%) lesions. Additional techniques to facilitate stent delivery (i.e., buddy wire, anchoring-balloon, or Guideliner catheter) were required in 5 lesions. In one case the XLIMUS DES finally failed to cross the target lesion. CONCLUSION: This prospective, single-center pilot study suggests that the tracking and lesion crossing performance quality of the XLIMUS DES ensures treatment of complex coronary artery lesions.

From bench to bedside: initial experience with the Primus drug-coated balloon catheter.

AIM: Drug-coated balloon (DCB) technology has emerged as a promising therapy particularly in the treatment of coronary in-stent restenosis. Although a variety of devices are available for clinical use, clinical outcomes have been variable and scope for significant improvement exists. METHODS: In a preclinical study, a total of 10 juvenile healthy farm pigs underwent catheter-based DCB deployment in coronary arteries with angiographic and pathological follow-up at 7 or 28 days. Animals were randomly allocated to the PRIMUS or Dior® DCB (N.=10 per group) and evaluated by histopathology and morphometric analysis. In a first-in-man clinical study a total of 19 consecutive patients presenting with restenosis within drug-eluting stents were treated with the PRIMUS DCB. Clinical follow-up was performed out to 6 months. RESULTS: Neointimal thickness was similar between the PRIMUS and Dior® DCB groups, while fibrin deposition and inflammation were more sustained in the PRIMUS group at 28 days. In 19 consecutive patients presenting with in-stent restenosis of drug-eluting stents, treatment with the PRIMUS DCB catheter resulted in high procedural efficacy. There were no adverse clinical events observed out to 6 months. CONCLUSION: The PRIMUS DCB demonstrates high preclinical safety and excellent acute performance and safety. Further studies are needed to delineate the relative merits of this novel DCB compared to other devices.

Renalguard system in high-risk patients for contrast-induced acute kidney injury.

Contrast-induced acute kidney injury (CI-AKI) predicts unfavorable outcomes. The use of the RenalGuard™® system, to create high urine output and fluid balancing, may be beneficial in preventing CI-AKI. The REMEDIAL II trial is a randomized, multicenter, investigator-driven trial addressing the prevention of CI-AKI in high risk patients. Consecutive patients with an estimated glomerular filtration rate (eGFR) ≤30 mL/min/1.73 m2 and/or a risk score ≥11 were randomly assigned to 1) sodium bicarbonate solution and N-acetylcysteine (NAC) (Control group) or 2) the RenalGuard therapy, that is, hydration with saline and NAC controlled by the RenalGuard System and furosemide (RenalGuard group). CI-AKI (defined as an increase of ≥0.3 mg/dL in the serum creatinine concentration at 48 hours after the procedure) occurred in 16/146 patients in the RenalGuard group (11%) and in 30/146 patients in the Control group (20.5%) (P=0.025; OR=0.47; 95% CI=0.24-0.92). Absolute changes in CyC at 24 hours (0.02±0.32 versus -0.08±0.26; P=0.002) and at 48 hours (0.12±0.42 versus -0.03±0.31; P=0.001), as well as the rate of in-hospital dialysis (4.1% versus 0.7%; P=0.056) were higher in the Control group. In conclusion, the RenalGuard therapy seems to be a promising new approach in preventing CI-AKI in high risk patients.

In vivo and in vitro assessment of pathways involved in contrast media-induced renal cells apoptosis.

Contrast-induced nephropathy accounts for >10% of all causes of hospital-acquired renal failure, causes a prolonged in-hospital stay and represents a powerful predictor of poor early and late outcome. Mechanisms of contrast-induced nephropathy are not completely understood. In vitro data suggests that contrast media (CM) induces a direct toxic effect on renal tubular cells through the activation of the intrinsic apoptotic pathway. It is unclear whether this effect has a role in the clinical setting. In this work, we evaluated the effects of CM both in vivo and in vitro. By analyzing urine samples obtained from patients who experienced contrast-induced acute kidney injury (CI-AKI), we verified, by western blot and immunohistochemistry, that CM induces tubular renal cells apoptosis. Furthermore, in cultured cells, CM caused a dose-response increase in reactive oxygen species (ROS) production, which triggered Jun N-terminal kinases (JNK1/2) and p38 stress kinases marked activation and thus apoptosis. Inhibition of JNK1/2 and p38 by different approaches (i.e. pharmacological antagonists and transfection of kinase-death mutants of the upstream p38 and JNK kinases) prevented CM-induced apoptosis. Interestingly, N-acetylcysteine inhibited ROS production, and thus stress kinases and apoptosis activation. Therefore, we conclude that CM-induced tubular renal cells apoptosis represents a key mechanism of CI-AKI.

How to treat diabetic patients with multivesseal disease in the DES era.

Patients with type 2 diabetes mellitus represent the 25% of those requiring myocardial revascularization. Choice of treatment in diabetic patients is much more controversial than in non-diabetics: this because coronary artery disease is more often complex and diffuse, left ventricular function is depressed, and concomitant multiple risk factors are present. These subset of patients experience worse outcomes than non diabetic patients undergoing either coronary artery bypass grafting (CABG) or percutaneous coronary interventions (PCI). Large randomized trials performed both in the early era of PCI and in the stent era suggest that CABG is superior to bare metal stent implantation in the treatment of diabetic patients with multivessel coronary artery disease. These findings are reflected in current guidelines, which favor CABG over PCI in most diabetics who require revascularization. However, substantial variability exists in practice patterns among individual hospital, suggesting a lack of clinical consensus. The major advantage of CABG over bare metal stent implantation in diabetic patients is the lower risk of repeat revascularization procedures through the follow-up. Better angiographic results have been demonstrated in the new era of drug-eluting stents (DES). Data from both the sirolimus and paclitaxel-eluting stents trials support the potential advantage of DES implantation both in diabetic and non-diabetic patients. Preliminary data from studies comparing DES versus CABG in diabetic patients with multivessel coronary artery disease suggests that 1) no significant difference exists in the 12-month rate of death, myocardial infarction and cerebrovascular events in patients treated with DES as compared to off-pump bypass surgery, 2) a difference of 7.1% in the rate of repeat revascularization at 12-month exists in favor of bypass surgery and 3) diabetic retinopathy identifies a subgroup with poor outcome after both percutaneous and surgical myocardial revascularization.

Selection of contrast media.

The pathophysiologic mechanisms of contrast-induced nephropathy (CIN) have been reviewed by Persson and Tepel. They focus on the renal response to contrast media (CM). In this section, we focus on the CM itself. Aspects of importance with regard to CIN include the route of administration, the volume of CM, the manner of X-ray attenuation, and the specific chemical structure of the CM.

Contrast-induced nephropathy: pharmacological prophylaxis.

Contrast media-associated acute renal failure represents the third most common cause of in-hospital renal function deterioration after decreased renal perfusion and post-operative renal insufficiency. Although generally benign, this complication is associated with a mortality rate ranging from 3.8 to 64%, depending on the increase of creatinine concentration. Multiple drugs have been tested in an attempt to prevent this complication. Central to the pathophysiology of contrast-induced nephrotoxicity (CIN) is an alteration in renal hemodynamics. In an effort to reverse these hemodynamic changes, vasodilators and diuretics have been tested as prophylactic drugs. However, their effectiveness has not been confirmed. Recently, considerable interest has resulted from the initial positive data on the effectiveness of prophylactic administration of antioxidant compounds, such as acetylcysteine and ascorbic acid. In this review, we focus on the effectiveness of pharmacologic therapies for preventing CIN.

New pharmacological protocols to prevent or reduce contrast media nephropathy.

Contrast media associated acute renal failure represents the third cause of in-hospital renal function deterioration after decreased renal perfusion and post-operative renal insufficiency. Although generally benign, this complication shows a mortality rate ranging from 3.8% to 64%, depending on the increase of creatinine concentration. The mechanism by which contrast-induced renal failure occurs is not well understood. Contrast agent-associated nephrotoxicity appears to be a result of direct contrast induced renal tubular epithelial cell toxicity and renal medullary ischemia. Furthermore, a key mechanism seems to be alteration in renal dynamics, probably caused by imbalances between vasodilator and vasoconstrictor factors, including the activities of nitric oxide, prostaglandins, endothelin and reactive oxygen species. Recommendations to prevent contrast-associated nephrotoxicity are: 1) periprocedural hydration, 2) use of a low osmolality contrast, and 3) limiting the amount of contrast agent. Recently, considerable interest has resulted from the preliminary positive data on the effectiveness of prophylactic administration of antioxidant compounds (such as acetylcysteine and ascorbic acid) and fenoldopam.

Clinical and angiographic outcome of directional atherectomy followed by stent implantation in de novo lesions located at the ostium of the left anterior descending coronary artery.

BACKGROUND: Lesions located at the ostium of the left anterior descending coronary artery (LAD) are considered an ideal target for directional atherectomy (DCA), but few data are available about the value of using this strategy before stenting in comparison with stenting alone. OBJECTIVES: To investigate the immediate and mid term clinical and angiographic results of DCA followed by stent implantation for ostial LAD lesions. DESIGN: Retrospective comparison of the immediate and mid term angiographic and clinical results of a series of 117 consecutive patients with de novo lesions located at the ostium of the LAD. Of these, 46 underwent DCA before stenting and 71 were treated with stenting alone. RESULTS: Technical success in the two groups was similar at around 98%. DCA plus stenting provided a larger minimum lumen diameter at the end of the procedure than stenting alone (3.57 (0.59) mm v 3.33 (0.49) mm, p = 0.022). There were no differences for in-hospital major adverse events (MACE) (7.5% for atherectomy plus stenting, and 5.3% for stenting alone; p = 0.41). All patients had clinical follow up at a mean of 7.9 (2.7) months. Angiographic follow up was done in 89 patients (76%) at a mean of 5.9 (2.2) months. The atherectomy plus stenting group had a larger minimum lumen diameter than the stenting group (2.79 (0.64) mm v 2.26 (0.85) mm, p = 0.004) and a lower binary restenosis rate (13.8% v 33.3%, p = 0.031). Six month MACE were reduced in the atherectomy plus stenting group (8.7% v 23.9%, p = 0.048). CONCLUSIONS: Debulking before stenting in de novo lesions located at the ostium of the LAD is safe and is associated with a high rate of technical success. Follow up data show that DCA plus stenting results in a significantly larger minimum lumen diameter and a lower incidence of restenosis than stenting alone.

Carotid artery stenting in the first 100 consecutive patients: results and follow up.

BACKGROUND: Carotid artery stenting is now used as an alternative to surgical endarterectomy. The availability of cerebral protection systems has expanded the area of application of this procedure. OBJECTIVE: To assess the feasibility, safety, and immediate and late clinical outcome in patients undergoing percutaneous carotid interventions. METHODS: Between January 1999 and December 2000, 100 consecutive patients with 102 carotid artery stenoses were treated (71 men, 29 women, mean (SD) age 67 (8) years): 49 had coronary artery disease, 28 had previous stroke or transient ischaemic attack (TIA). On the basis of the Mayo Clinic carotid endarterectomy risk scale, 73 patients were grade III-IV and 13 grade VI. RESULTS: Baseline diameter stenosis was 78.8 (10)%, with a mean lesion length of 12.6 (5.8) mm. Angiographic success was obtained in 99 lesions (97.0%) with a final diameter stenosis of 2.4 (3.5)%. Procedural success was obtained in 96 patients (96%). Selective cannulation of three carotid arteries was impossible owing to severe vessel tortuosity. Carotid stenting was performed in 97 of the treated lesions, and protection devices were used in 67 lesions. In-hospital complications occurred in seven patients (six TIA, one (category 1) minor stroke). No major stroke or death occurred. All patients were discharged from the hospital after an average of 2.5 days. At 12 (6.2) months of follow up restenosis occurred in three patients (3.4%) (one patient with carotid occlusion had TIA). Six patients had died: two from cerebrovascular events (5 and 11 months after the procedure) and four from cardiovascular causes. CONCLUSIONS: Carotid stenting appears feasible and safe, with few major complications. Long term follow up is affected by a high incidence of cardiovascular mortality.

Discrepancy between angiography and intravascular ultrasound when analysing small coronary arteries.

AIMS: A small reference diameter may be the consequence of high plaque burden and diffuse disease. The reference vessel diameter in small coronary arteries may vary according to the method of measurement used. We endeavoured to confirm the difference between data from examinations conducted using angiography with that revealed by intravascular ultrasound. METHODS AND RESULTS: Between March 1993 and October 1999, 344 consecutive patients with 419 lesions in small vessels (< or =2.75 mm, Small group) and 953 patients with 1161 lesions in large vessels (Large group) underwent intravascular ultrasound-guided percutaneous transluminal angioplasty in our Institution. The mean difference between the intravascular ultrasound and the angiographic reference diameter (Delta(IVUS-Angio)) was 1.3+/-0.5 mm in the Small group and 1.0+/-0.6 mm in the Large group (P<0.001). There was a stronger correlation between plaque burden and Delta(IVUS-Angio)in the Small group (r=0.80, P<0.001) than in the Large group (r=0.59, P<0.001). An Delta(IVUS-Angio)> or =0.30 mm occurred in 99.5% of cases in the Small group and in 90% in the Large group (P<0.001). An Delta(IVUS-Angio)> or =0.50 mm occurred in 96% of case in the Small group and 80% in the Large group (P<0.001). Predictors of Delta(IVUS-Angio)> or =0.50 in the Small group were: proximal or middle lesion site, vessel type (left anterior descending artery, diagonal and obtuse marginal branches) and female sex. An Delta(IVUS-Angio)> or =1.0 mm occurred in 71% of cases in the Small group and in 49% in the Large group (P<0.001). Predictors of Delta(IVUS-Angio)> or =1.0 mm in the Small group were: proximal or middle lesion site, female sex, and lesion length. CONCLUSIONS: A high percentage of vessels measuring < or =2.75 mm are large vessels with a high plaque burden. This condition is particularly prevalent in females, with lesions in the proximal or middle left anterior descending artery, and in obtuse marginal and diagonal branches.

Immediate and long-term clinical and angiographic results from Wiktor stent treatment for true bifurcation narrowings.

From January 1996 to December 1998, 90 consecutive patients with true bifurcation lesions underwent percutaneous coronary angioplasty with Wiktor stent implantation in our centers. In 1 group (group I, n = 45), a simple approach (main vessel stenting and balloon angioplasty of the side branch) was pursued. In the other group (group II, n = 45), both the main vessel and the side branch were stented ("T" technique). There was no significant difference in clinical and angiographic characteristics between the 2 groups. Angiographic and procedural successes were 100% and 95.6%, respectively, in both groups. Angiographic results for the side branch were better in group II than in group I. In-hospital and long-term (12 month) major cardiac events were similar in the 2 groups. Target lesion revascularization was 15.5% in group I and 35.5% in group II (p = 0.12). In the main vessel, restenosis rate was 12.5% in group I and 25% in group II (p = 0.15). In the side branch, restenosis rate was 37.5% in group II and 12.5% in group I (p = <0.05; odds ratio 2.42; 95% confidence interval 1.05 to 6.26). Event-free probability at 12 months was 61% in group II and 80% in group I (p = 0.10). When dealing with true bifurcation lesions, a simple strategy is associated with a lower risk of restenosis in the side branch. In contrast, a complex approach does not appear to give any benefit in terms of early or long-term outcome or restenosis rate.

Cutting balloon angioplasty for the treatment of in-stent restenosis: a matched comparison with rotational atherectomy, additional stent implantation and balloon angioplasty.

OBJECTIVES: The purpose of the study was to determine whether cutting balloon angioplasty (CBA) has advantages over other modalities in treatment of in-stent restenosis (ISR). BACKGROUND: Controversies exist regarding optimal treatment for ISR. Recently, CBA emerged as a tool in management of ISR. METHODS: A total of 648 lesions treated for ISR were divided into four groups according to the treatment strategy: CBA, rotational atherectomy (ROTA), additional stenting (STENT), and percutaneous transluminal coronary angioplasty (PTCA). Following the matching process, 258 lesions were entered into the analysis. RESULTS: Baseline clinical and angiographic characteristics were similar among the groups (p = NS). Acute lumen gain was significantly higher in the STENT group (2.12 +/- 0.7 mm), whereas in the CBA group the gain was similar to one achieved following ROTA and following PTCA (1.70 +/- 0.6 vs. 1.79 +/- 0.5 mm and 1.56 +/- 0.7 mm, respectively; p = NS). The lumen loss at follow-up was lower for the CBA versus ROTA and versus STENT (0.63 +/- 0.6 vs. 1.30 +/- 0.8 mm and 1.36 +/- 0.8 mm, respectively; p < 0.0001), yielding a lower recurrent restenosis rate (20% vs. 35.9% and 41.4%, respectively; p < 0.05). By multivariate analysis, CBA (odds ratio [OR] = 0.17; confidence interval [CI], 0.06 to 0.51; p = 0.001) and diffuse restenosis type at baseline (OR = 2.07; CI, 1.15 to 3.71; p = 0.02) were identified as predictors of target lesion revascularization. CONCLUSIONS: We conclude that CBA is a safe and efficient technique for treatment of ISR, with immediate results similar to atheroablation and better clinical and angiographic outcomes at follow-up. This approach might be implemented as a viable option in management of focal ISR and to prepare diffuse ISR for brachytherapy treatment.

Predictors of re-occlusion after successful recanalization of chronic total occlusion.

UNLABELLED: The objective of this study was to highlight the incidence and predictors of re-occlusion after successful recanalization of chronic total coronary occlusions. METHODS AND RESULTS: Following successful recanalization and stent implantation in 716 coronary lesions (665 patients) with chronic total occlusion, four hundred and five (56.6%) lesions (375 patients) underwent repeat angiography within 6 months. Restenosis (> or = 50% lumen narrowing) was observed in 151 (37.3%) lesions; forty-three (10.6%) of these lesions had complete re-occlusion and constituted the study population. In this group, final angiographic minimal lumen diameter (MLD) was 2.6 +/- 0.51 mm and final percent diameter stenosis was 18 +/- 11. Univariate analysis revealed significant correlation between re-occlusion and restenotic lesions, final balloon diameter, final percent diameter stenosis, final angiographic MLD, number of stents per lesion and total stent length. By multivariate analysis, the only independent predictor of re-occlusion was total stent length (OR = 1.46, 95% CI = 1.12-1.82; p = 0.0069). CONCLUSION: Re-occlusion occurs in about 11% of cases after stenting chronic total occlusion. The most important predictor of re-occlusion seems to be stent length.

Determinants and clinical significance of natriuretic peptides and hypertrophic cardiomyopathy.

AIMS: Atrial and brain natriuretic peptide levels closely reflect impaired left ventricular function in patients with heart failure. In the present study we assessed the determinants and the clinical significance of atrial and brain natriuretic peptide plasma levels in hypertrophic cardiomyopathy. METHODS AND RESULTS: In 44 patients with hypertrophic cardiomyopathy (40+/-15 years) we evaluated: (a) atrial and brain natriuretic peptide plasma levels; (b) left ventricular hypertrophy; (c) left ventricular ejection fraction; (d) transmitral and pulmonary venous flow velocity patterns, and left atrial fractional shortening; (e) left ventricular outflow tract gradient; (f) maximal oxygen consumption. Left ventricular hypertrophy influenced only brain natriuretic peptide levels (r=0.32;P<0.05). Atrial and brain natriuretic peptide plasma levels did not correlate with left ventricular ejection fraction, but correlated with left ventricular outflow tract gradient (r=0.35;P<0.05; and r=0.40, P=0.022, respectively) and left atrial fractional shortening (r=-0.57;P<0.001, and r=-0.35;P<0.05, respectively). Atrial but not brain natriuretic peptide plasma levels were inversely related to maximal oxygen consumption (r=-0.35;P<0.05). By stepwise multiple regression analysis, left atrial fractional shortening and left ventricular outflow tract gradient were the only predictors of atrial and brain natriuretic peptide plasma levels, respectively. CONCLUSIONS: In hypertrophic cardiomyopathy, atrial natriuretic peptide plasma levels are mainly determined by diastolic function: this explains the relationship with exercise tolerance. In contrast, brain natriuretic peptide plasma levels are mainly determined by left ventricular outflow tract gradient.

Emergency stenting to treat neurological complications occurring after carotid endarterectomy.

OBJECTIVES: The purpose of this study was to assess the efficacy of emergency stent implantation for the treatment of perioperative stroke after carotid endarterectomy (CEA). BACKGROUND: Carotid endarterectomy has been proven safe and effective in reducing the risk of stroke in symptomatic and asymptomatic patients with >60% carotid artery stenosis. However, perioperative stroke has been reported in 1.5% to 9% of CEA cases. The management of such a complication is challenging. Recently, percutaneous transluminal carotid angioplasty with stent deployment has emerged as a valuable and alternative strategy for the treatment of carotid artery disease. METHODS: Between April 1998 and February 2000, 18 of the 995 patients (1.8%) who had CEA in our institution experienced perioperative major or minor neurological complications. Of these, 13 patients underwent emergency carotid angiogram and eventual stent implantation, whereas the remaining five had surgery re-exploration. RESULTS: Carotid angiogram was performed within 20+/-10 min and revealed vessel flow-limiting dissection (five cases) or thrombosis (eight cases). Percutaneous transluminal carotid angioplasty with direct stenting (self-expandable stent) was performed in all 13 cases. Angiographic success was 100%. Complete remission of neurological symptoms occurred in 11 of the 13 patients treated by stent implantation and in one of the five patients treated by surgical re-exploration (p = 0.024). CONCLUSIONS: Stent implantation seems to be a safe and effective strategy in the treatment of perioperative stroke complicating CEA, especially when carotid dissection represents the main anatomic problem.

Assessment of the functional significance of coronary lesions using a monorail catheter.

Myocardial fractional flow reserve (FFR) < 0.75 is a reliable index of a functionally severe coronary stenosis. FFR is best assessed by a sensor-tipped pressure monitoring guidewire (PW). The purpose of this study was to assess whether a multifunctional probing catheter (MFP), a 3 French dual-lumen monorail catheter, can be used to accurately measure intracoronary pressure and FFR. In 35 lesions (35 patients; learning group), we calculated FFR by both PW (FFRPW) and MFP (FFRMFP). Using ROC analysis, the FFRMFP value of 0.65 had the highest sensitivity with the FFRPW < 0.75. FFRMFP cut-off (0.65) was tested in 40 patients (testing group). In all cases, lumen diameter was documented by an intracoronary ultrasound examination. In the learning group, the FFRPW was 0.82 +/- 0.17 and FFRMFP was 0.70 +/- 0.23 (r = 0.88; p < 0.001). The FFRMFP cut-off value (0.65) correctly predicted the FFRPW in 37/40 cases in the testing group. In the 3 discordant cases, FFR was critical (< 0.65) by MFP and normal (> 0.75) by PW. In all these cases, minimal lumen cross-sectional area was < 2.8 mm2. When FFRMFP is > 0.65, FFRPW is always > 0.75. These data demonstrate that even with larger cross-sectional area than a pressure wire, the MFP catheter can easily and reliably be used to assess the functional severity of coronary stenosis.

Characterization of total occlusions with intracoronary ultrasound: the importance of the duration of occlusion.

OBJECTIVE: To assess the impact of the occlusion duration on the characteristics of coronary occlusive plaques. BACKGROUND: The percutaneous recanalization of chronic total coronary occlusions is a technically demanding and yet often unsuccessful procedure due to unfavorable morphological changes described by histology but not well defined in vivo. METHODS: Thirty-five consecutive total occlusions of > or = 1 month duration in previously untreated native coronary arteries were studied using intracoronary ultrasound following dilatation with a 1.5 mm balloon. Plaque characteristics of lesions with an occlusive duration of > or = 3 months (old occlusions) and those of < 3 months (recent occlusions) were then compared. The ultrasound cross-section where there was maximal plaque accumulation at the site of occlusion was analyzed for its qualitative and quantitative characteristics. The lesion remodeling index was defined as the vessel area at occlusion divided by the vessel area at a proximal reference. RESULTS: The old occlusion group comprised 11 lesions whereas 16 lesions were found in the recent occlusion group; the occlusion duration was undetermined in the remaining 8 lesions, and the mean occlusion duration was found to be 4.9 +/- 4.3 months, over a range of 1 36 months. The baseline clinical and angiographic characteristics were similar in the 2 groups. The lesion remodeling index was found to be significantly lower in older occlusions than in the more recent occlusions (0.75 +/- 0.14 vs. 1. 06 +/- 0.25; p = 0.007) and the duration of the occlusion also correlated with the length of calcified segment as determined by ultrasound (p = 0.040), and with a smaller angiographic proximal reference diameter (p = 0.043). CONCLUSION: Long-standing occlusions undergo lesion shrinkage and exhibit more extensive calcification.

Intravascular ultrasound criteria for the assessment of the functional significance of intermediate coronary artery stenoses and comparison with fractional flow reserve.

The functional significance of coronary artery stenoses of intermediate severity is important in determining strategy in patient care. Intravascular ultrasound (IVUS) is often used to evaluate coronary stenosis severity. However, at present, few data are available about the role IVUS in the assessment of functional significance of intermediate lesions. Myocardial fractional flow reserve (FFR) <0.75 is a reliable index of a functionally severe coronary stenosis. In 53 lesions we assessed (1) by pressure wire: FFR (index of functional significance), and (2) by IVUS: minimal lumen cross-sectional area (MLA, square millimeters), minimal lumen diameter (MLD, millimeters), lesion length (millimeters), and percent area stenosis at the lesion site. By regression analysis, percent area stenosis and lesion length had a significant inverse correlation with FFR (r = -0.58, p <0.001, r = -0.41, p <0.004, respectively). MLD and MLA showed a significant positive relation with FFR (r = 0.51, p <0.001, r = 0.41, p <0.004, respectively). By using a receiver operating characteristic (ROC) curve, we identified a percent area stenosis > 70% (sensitivity 100%, specificity 68%), a MLD < or = 1.8 mm (sensitivity 100%, specificity 66%), a MLA < or =4.0 mm2 (sensitivity 92%, specificity 56%), and a lesion length of >10 mm (sensitivity 41%, specificity 80%) to be the best cut-off values to fit with a FFR <0.75. The combined evaluation of both percent area stenosis and MLD made the IVUS examination more specific (sensitivity 100%, specificity 76%). In 53 intermediate coronary lesions found by angiography, IVUS area stenosis >70%, MLD < or =1.8 mm, MLA < or =4.0 mm2, and lesion length > 10 mm reliably identified functionally critical intermediate coronary stenoses.