Angiographic changes thirty minutes following percutaneous transluminal coronary angioplasty

A randomized trial of aspirin versus cilostazol therapy after successful coronary stent implantation

Percutaneous transluminal coronary angioplasty (PTCA) is widely used to treat patients with ischemic heart disease, but the procedure involves a number of problems, including acute coronary occlusion and restenosis. Although stents have proved useful for preventing post-PTCA restenosis, especially elastic recoil during the acute phase, no method has yet been established to prevent restenosis caused by vascular smooth muscle cell proliferation in the late phase. Cilostazol selectively inhibits the 3'5'-cyclic-nucleotide phosphodiesterase (PDE) III (cyclic guanosine monophosphate-inhibited PDE) of the cyclic adenosine monophosphate PDE family; it also has antithrombotic and vasodilating effects, as well as an inhibitory effect on vascular smooth muscle cell proliferation through PDE III inhibition. From November 1995 to March 1997, the usefulness of cilostazol versus aspirin in preventing subacute thrombosis and restenosis was studied in 70 patients (55 men and 15 women; 82 total lesions) who had undergone successful elective Palmaz-Schatz stent implantation. Patients were randomly allocated to receive aspirin 81 mg/d (40 patients with 45 lesions) or cilostazol 200 mg/d (30 patients with 37 lesions) alone. There was no difference in patients or angiographic characteristics between these groups. No subacute thrombosis, acute complications (ie, death, emergent coronary artery bypass grafting, or hemorrhagic complications), or drug side effects were found in the cilostazol group. The minimal lumen diameter (mean +/- SD) at follow-up was 1.89 +/- 1.08 mm in the aspirin group (41 lesions, 5.63 +/- 1.74 months after stent implantation) and 2.34 +/- 0.74 mm in the cilostazol group (35 lesions, 5.14 +/- 1.91 months after stent implantation), revealing statistically significant dilatation in the cilostazol group. The restenosis rate was 26.8% in the aspirin group, compared with 8.6% in the cilostazol group; this difference was statistically significant. Administration of cilostazol alone after the implantation of intracoronary Palmaz-Schatz stents was useful for the prevention of subacute thrombosis and restenosis.

Incidence and treatment of elastic recoil occurring in the 15 minutes following successful percutaneous transluminal coronary angioplasty

This study was performed (1) to assess the incidence and magnitude of elastic recoil occurring within 15 minutes of successful coronary angioplasty, and (2) to determine the effect of subsequent additional balloon inflations on coronary luminal diameter in patients displaying substantial recoil. The coronary angiograms of 50 consecutive patients who underwent a successful percutaneous transluminal coronary angioplasty were analyzed using computer-assisted quantitative analysis. The patients were divided into 2 groups based on the magnitude of early elastic recoil following angioplasty: those with < or = 10% (group I, n = 30) and those with > 10% (group II, n = 20) loss of minimal luminal diameter as assessed by comparing the angiogram obtained immediately after successful angioplasty with that obtained 15 minutes later. The 2 groups were similar in clinical, angiographic, and procedural characteristics. Of the 20 group II subjects, 18 (90%) underwent repeat balloon dilatations, and 2 patients (10%) had no further intervention. After additional balloon inflations were performed in these 18 patients, 16 (90%) had a final result with < 10% loss of minimal luminal diameter 15 minutes later. In conclusion, elastic recoil 15 minutes after apparently successful percutaneous transluminal coronary angioplasty is frequent, occurring in approximately 40% of patients, and is attenuated in 90% of subjects with additional balloon inflations. The resultant larger lumen diameter may exert a salutary effect on long-term outcome.

Endothelium dependent and independent responses in coronary artery disease measured at angioplasty

OBJECTIVE--To investigate the effects of substance P and papaverine, two drugs that increase coronary blood flow by different mechanisms, on vasomotion in stenotic coronary arteries at percutaneous transluminal coronary angioplasty (PTCA). DESIGN--Coronary blood flow responses to substance P and papaverine were measured in stenotic coronary arteries at the time of PTCA with quantitative angiography and a Doppler flow probe. SETTING--A cardiothoracic referral centre. PATIENTS--15 patients undergoing elective PTCA of a discrete epicardial coronary artery stenosis. INTERVENTIONS--Pharmacological coronary flow reserve was determined with papaverine 5-10 minutes before and after successful PTCA. Endothelium dependent responses to 2 minute infusions of substance P (10-15 pmol.min-1) were assessed immediately before PTCA. MAIN OUTCOME MEASURES--Coronary blood flow responses and changes in epicardial coronary artery area at stenotic, proximal, and distal sites with papaverine and substance P. RESULTS--Stenotic sites dilated with papaverine before PTCA (17.7%(6.9%) (mean (SEM)) area increase, p < 0.05 v baseline). Substance P dilated stenotic sites (16.8%(5.7%) area increase, p < 0.05) and proximal (14.3%(5.4%), p < 0.05) and distal sites (41.7%(9.3%), p < 0.005). Coronary flow reserve increased but did not reach normal values after PTCA (2.3(0.4) before PTCA v 3.0(0.4) after PTCA, p < 0.05) and was associated with an increase in peak flow with papaverine. Angioplasty did not alter baseline flow. After PTCA papaverine caused significant vasoconstriction at the stenotic site (-13.6%(4.3%) area decrease, p < 0.05). There was a negative correlation (r = -0.68, p < 0.05) between the dilator response with papaverine before PTCA and the constrictor response after PTCA. CONCLUSIONS--Substance P causes endothelium dependent dilatation in atheromatous coronary arteries, even at sites of overt atheroma. The cause of the paradoxical constrictor response to papaverine after PTCA is uncertain, but unopposed flow mediated vasoconstriction (the myogenic response) after balloon induced endothelial denudation may be one of several contributory factors.

Serial angiographic observations after successful directional coronary atherectomy

This study focuses on the early and late angiographic evolution observed in 82 patients with coronary artery disease who were successfully treated by directional coronary atherectomy (DCA) without adjunctive balloon angioplasty. Qualitative inspections and quantitative measurements were obtained from a selected angled-view projection in the following conditions: (1) before treatment; (2) immediately after treatment; (3) the day after atherectomy; (4) 1 month after; and (5) 6 months after. The appearance of the treated segment 24 hours after the procedure did not differ in 79 patients from that observed immediately after DCA; silent total occlusion occurred in two patients, and one had an aneurysm at the site of resection (all three patients were excluded from the analysis). At the 1-month study restenosis developed in 3 (3.6%) patients; the remaining 76 had identical appearances, with no evidence of renarrowing of the lumen. However, from 1 to 6 months after the procedure restenosis developed in 35 of the remaining 76 (46%) patients, and 41 patients were free of restenosis and symptoms. These findings, which show that early elastic recoil does not occur after successful DCA, are different from the changes observed after balloon angioplasty. At the 1-month observation restenosis is an infrequent but possible phenomenon (3.8%). From this point the healing of the arterial wall leads to no or mild renarrowing (late success); an exaggerated proliferative response produces restenosis.

Reliability of quantitative coronary angiography of the target lesion immediately and 1 day after coronary balloon and excimer laser angioplasty

OBJECTIVES

This prospective trial was performed to evaluate the impact of the morphologic complications of angioplasty on the reliability and results of quantitative angiographic assessment of the residual stenosis.

BACKGROUND

Postintervention quantitative coronary analysis is limited by a variety of such complications.

METHODS

In 199 patients undergoing an early control angiographic study within 24 h after coronary balloon or excimer laser angioplasty (24-h study), detailed quantitative angiographic measurements were performed on the target lesion immediately after intervention and at the 24-h study. Reproducibility of quantitative arteriography was determined by repeat measurements on the same angiogram.

RESULTS

Intraobserver/interobserver variability was significantly higher (p < 0.0001/p < 0.03) for the postintervention angiogram than for the 24-h angiogram. Patients were classified into three subgroups with respect to the occurrence of angiographic complications or chest pain after intervention. In patients with angiographic complications after balloon angioplasty alone/stand-alone laser angioplasty/laser angioplasty with adjunctive balloon dilation, a significant difference in mean minimal lumen diameter (p = 0.0001/p = 0.03/p = 0.035) was observed between the immediate postintervention and 24-h angiogram. In patients without angiographic complications or patients with recurrent chest pain undergoing balloon angioplasty, stand-alone or adjunctive laser angioplasty, mean minimal lumen diameter remained nearly unchanged (p = NS).

CONCLUSIONS

Angiographic measurements of the target lesion immediately after angioplasty were significantly less reliable than measurements obtained at 24 h after angioplasty in patients with angiographic complications. The occurrence of postintervention vascular complications was associated with significant early lesion changes between the immediate postangioplasty and the 24-h angiogram.

Influence of elastic recoil on restenosis after successful coronary angioplasty in unstable angina pectoris

The elastic behavior of the dilated coronary vessel has been reported to affect the immediate results of coronary angioplasty. To determine whether elastic recoil may also influence the long-term restenosis process, 98 consecutive patients with unstable angina and 1-vessel disease were studied. An automated coronary quantitative program was used for the assessment of balloon and coronary luminal diameters. Elastic recoil was defined as the percent reduction between minimal balloon diameter at the highest inflation pressure and minimal lesion diameter immediately after coronary angioplasty. Follow-up coronary arteriography was performed 8 to 12 months after the procedure in all patients. The mean elastic recoil averaged 17.7 +/- 16% and was correlated to the degree of residual stenosis immediately after coronary angioplasty (r = 0.64; p < 0.001). Restenosis, defined as > 50% diameter stenosis at follow-up, developed in 53 patients (54%). There was no correlation between the degree of elastic recoil and the changes in minimal lesion diameter observed during follow-up, whereas a positive correlation between the amount of elastic recoil and the incidence of restenosis was documented (r = 0.84; p < 0.05). Thus, the elastic properties of the dilated vessel do not influence the active process of restenosis. However, because elastic recoil negatively influences the initial results of angioplasty, it is more likely that further reductions in lumen diameter during follow-up can reach a threshold of obstruction considered critical for a binary definition of restenosis.

Comparison of acute elastic recoil after directional coronary atherectomy versus standard balloon angioplasty

We evaluated intraprocedural "elastic recoil" in 25 patients (22 men and 3 women) undergoing directional coronary atherectomy (DCA) of left anterior descending stenoses, and compared these with 25 temporally-matched (14 men and 11 women) patients having balloon angioplasties (PTCA). Quantitative arteriography was performed using the Coronary Measurement System (Leiden, The Netherlands), with "elastic recoil" defined as the difference in maximum device or balloon size minus residual minimum diameter. In addition, we determined the effects of relative device size, specific anatomic location (proximal/mid artery), lesion length, eccentricity (symmetry index), and dystrophic calcification on acute "recoil" severity after both procedures. Although initial coronary stenoses were similar (minimum stenotic diameter, DCA = 0.59 +/- 0.20 mm versus PTCA = 0.55 +/- 0.23 mm, p = NS), less "elastic recoil" was observed after atherectomy (DCA = 0.83 +/- 0.57 mm versus PTCA = 1.26 +/- 0.56 mm, p < 0.01), and this was confirmed by absolute recoil/maximum device size ratios (DCA = 23.5 +/- 16.0% versus PTCA = 41.6 +/- 13.8%, p < 0.01). Acute "elastic recoil" was also influenced by maximum device size/"normal" coronary artery ratios [(ratio < 0.9, DCA = 0.26 +/- 0.10 mm versus PTCA = 0.84 +/- 0.13 mm, p < 0.01); (ratio 0.9 to 1.1, DCA = 0.69 +/- 0.41 mm versus PTCA 0.75 +/- 0.32 mm, p = NS); (ratio > 1.1, DCA = 1.09 +/- 0.64 mm versus PTCA = 1.59 +/- 0.48 mm, p < 0.05)].(ABSTRACT TRUNCATED AT 250 WORDS)

Acute outcome of directional coronary atherectomy vs standard balloon angioplasty in de novo left anterior descending stenoses

To assess the immediate outcome of directional coronary atherectomy (DCA) versus standard balloon angioplasty (PTCA) in de novo left anterior descending coronary stenoses, 25 consecutive atherectomies (22 men, 3 women) performed at The Toronto Hospital, between July 1990 and March 1991 were compared with 25 (14 men, 11 women) temporally matched successful angioplasties. Coronary stenoses were analyzed by quantitative arteriography, using the Coronary Measurement System (Leiden, The Netherlands), with estimation of transstenotic hemodynamics by fluid dynamic equations. Before and after procedure qualitative blood flow (TIMI criteria) was also evaluated, as was intimal haziness and coronary dissection. In comparison to PTCA, coronary atherectomy produced less residual minimum stenotic diameter (DCA, 2.75 +/- 0.55 vs PTCA, 1.70 +/- 0.44 mm, p < 0.001), and relative percent diameter stenosis (DCA, 17.9 +/- 10.7 vs PTCA, 34.4 +/- 10.7 percent, p < 0.001), with less transstenotic obstructive gradient (DCA, 0.2 +/- 0.2 vs PTCA, 1.0 +/- 1.5 mm Hg, p < 0.05), and greater estimated stenotic flow reserve (DCA, 4.86 +/- 0.15 vs PTCA, 4.50 +/- 0.48 x baseline, p < 0.05). Coronary atherectomy "normalized" TIMI flow patterns in virtually all patients (DCA, 2.96 +/- 0.20 vs PTCA, 2.72 +/- 0.45, p < 0.05), while creating less intimal haziness (DCA, 10/25 [40 percent] vs PTCA, 23/25 [92 percent], p < 0.01), and coronary dissection (DCA, 6/25 [24 percent] vs PTCA, 16/25 [64 percent], p < 0.05). Therefore, when compared with standard balloon angioplasty, DCA produces less residual stenosis, better transstenotic hemodynamics, while decreasing the frequency of coronary artery damage, in de novo left anterior descending stenoses.

Combination balloon-ultrasound imaging catheter for percutaneous transluminal angioplasty. Validation of imaging, analysis of recoil, and identification of plaque fracture

BACKGROUND

We investigated the hypothesis that an ultrasound transducer positioned within an angioplasty balloon could be used to perform quantitative assessment of arterial dimensions before and after percutaneous transluminal angioplasty (PTA) and to identify certain mechanical alterations consequent to PTA, including vascular wall recoil and the initiation of plaque fractures.

METHODS AND RESULTS

A combination balloon-ultrasound imaging catheter (BUIC) that houses a 20-MHz ultrasound transducer within and halfway between the proximal and distal ends of an angioplasty balloon was used to perform PTA in 10 patients with peripheral vascular disease. Each PTA site was also evaluated before and after PTA by standard (nonballoon) intravascular ultrasound (IVUS) technique. In eight patients in whom satisfactory images were recorded with the BUIC before PTA, luminal cross-sectional area (XSA) of stenotic sites (0.10 +/- 0.01 cm2) did not differ significantly from measurements of XSA by IVUS (0.09 +/- 0.01 cm2, p = NS). Likewise, minimum luminal diameter (Dmin) measured by BUIC (0.34 +/- 0.02 cm) was similar to that measured by IVUS (0.33 +/- 0.01 cm, p = NS). In nine patients in whom satisfactory images were recorded with the BUIC after PTA, XSA measured by BUIC (0.29 +/- 0.03 cm2) did not differ significantly from XSA measured by IVUS (0.30 +/- 0.03 cm2, p = NS). Dmin measured by BUIC after PTA (0.57 +/- 0.02 cm) was also similar to Dmin measured by IVUS (0.57 +/- 0.03 cm, p = NS). After PTA, XSA and Dmin measured immediately after deflation were significantly less than balloon XSA and diameter at full inflation, indicating significant elastic recoil of the dilated site. For the nine patients in whom post-PTA images were satisfactory for quantitative analysis, including four patients in whom recoil was 39%, 46%, 50%, and 61%, percent recoil measured 28.6 +/- 7.2%. Finally, plaque fractures were identified on-line in six of 10 patients (60%); in each case, initiation of plaque fracture was observed at inflation pressures of 2 atm or less.

CONCLUSIONS

The results of this preliminary human investigation indicate that an ultrasound transducer positioned within an angioplasty balloon can be used to perform quantitative and qualitative analyses of lumen-plaque-wall alterations immediately preceding, during, and immediately after PTA in patients with peripheral vascular disease.

Restenosis after percutaneous transluminal coronary angioplasty: pathologic observations in 20 patients

Histopathologic examination was performed in 20 patients undergoing antemortem coronary angioplasty. Thirty-four lesions were dilated and the interval between coronary angioplasty and death ranged from several hours to 4 years. Intimal proliferation of smooth muscle cells, as a major cause of restenosis, was observed in 83% to 100% of 28 lesions examined 11 days to 2 years after coronary angioplasty. In 20 lesions examined within 6 months, proliferating smooth muscle cells were predominantly of the synthetic type and there was abundant extracellular matrix substance chiefly composed of proteoglycans. In eight lesions examined between 6 months and 2 years, contractile type smooth muscle cells were dominant and extracellular matrix was composed chiefly of collagen. In three lesions examined after 2 years, evidence of antemortem coronary angioplasty was hardly identifiable and these lesions were almost indistinguishable from conventional atherosclerotic plaque. These temporal changes in histologic pattern provide a pathologic background for clinical reports that restenosis is predominantly found within 6 months after coronary angioplasty. Morphometric analysis revealed that the extent of intimal proliferation was significantly greater in lesions with evidence of medial or adventitial tears than in lesions with no or only intimal tears.

Vascular reactivity after balloon angioplasty in an atherosclerotic rabbit

Alterations in vessel wall reactivity (VR) at or adjacent to the dilation site after balloon angioplasty (BA) may vary according to the inflation protocol and the time after angioplasty and may influence outcome. In 64 atherosclerotic rabbit femoral arteries, we evaluated VR after BA with intravenous ergonovine (ERGO) (40 micrograms/min for 5 minutes) and intra-arterial nitroglycerin (NTG) (2,500 micrograms single bolus) 24-72 hours and 28 days after BA. Comparisons were made with atherosclerotic, nonangioplastied, age-matched controls. BA was standardized to three 1-minute inflations, each 1 minute apart. For each balloon size, 2.5- (appropriate size) or 3.0-mm (oversized) vessels were allocated to either 5 or 10 atm inflation pressure. For the analysis, four groups were compared: Group 1, 3.0/5; group 2, 3.0/10; group 3, 2.5/5, and group 4, 2.5 mm/10 atm. Angiographic diameters were measured at, proximal, and distal to the lesion at baseline, 10 minutes after ERGO, and 5 minutes after NTG. Angiograms were measured with electronic calipers by two blinded observers. All segments of control vessels vasoconstricted to ERGO and vasodilated to NTG (p less than 0.05 versus baseline), indicating a normal response. At 24-72 hours after dilatation, the angioplasty sites for all inflation pressure/balloon size combinations were not responsive to either ERGO or NTG. All segments distal to the dilatation sites vasoconstricted to ERGO and dilated to NTG (p less than 0.05 versus baseline), indicating a normal response. Proximal segments of vessels dilated with a 2.5-mm balloon (appropriate size) responded positively to both stimuli (p less than 0.05). Those vessels dilated with a large balloon (3.0 mm) were nonreactive in the segment proximal to the angioplasty site. Twenty-eight days later angioplasty sites dilated with a 2.5-mm balloon (appropriately sized) regained reactivity; however, segments dilated with a large balloon (3.0 mm) remained unresponsive. All proximal segments, including those from vessels dilated with a large balloon, reacted positively. All distal segments reacted appropriately. Restenosis rates were not different between the over- and appropriately sized balloon groups. These data demonstrate that immediately after angioplasty, vessels lose reactivity at the dilatation site. Those vessels dilated with the smaller-size balloon (2.5 mm) regained reactivity. For large balloons, reactivity is not regained at 28 days. For segments proximal to the site of dilatation, transient loss of reactivity is seen only when a large balloon is used. Thus, acute closure originating at the site of dilatation is not a result of spasm.(ABSTRACT TRUNCATED AT 400 WORDS)

Restenosis after successful percutaneous transluminal coronary angioplasty: serial angiographic follow-up of 229 patients

To further understand the temporal mode and mechanisms of coronary restenosis, 229 patients were studied by prospective angiographic follow-up on day 1 and at 1, 3 and 6 months and 1 year after successful percutaneous transluminal coronary angioplasty. Quantitative measurement of coronary stenosis was achieved by cinevideodensitometric analysis. Actuarial restenosis rate was 12.7% at 1 month, 43.0% at 3 months, 49.4% at 6 months and 52.5% at 1 year. In 219 patients followed up for greater than or equal to 3 months, mean stenosis diameter was 1.91 +/- 0.53 mm immediately after coronary angioplasty, 1.72 +/- 0.52 mm on day 1, 1.86 +/- 0.58 mm at 1 month and 1.43 +/- 0.67 mm at 3 months. In 149 patients followed up for greater than or equal to 6 months, mean stenosis diameter was 1.66 +/- 0.58 mm at 3 months and 1.66 +/- 0.62 mm at 6 months. In 73 patients followed up for 1 year, mean stenosis diameter was 1.65 +/- 0.56 mm at 6 months and 1.66 +/- 0.57 mm at 1 year. Thus, stenosis diameter decreased markedly between 1 month and 3 months after coronary angioplasty and reached a plateau thereafter. In conclusion, restenosis is most prevalent between 1 and 3 months and rarely occurs beyond 3 months after coronary angioplasty.