Randomised trial of elective stenting after successful percutaneous transluminal coronary angioplasty of occluded coronary arteries

Background—The value of angioplasty in occluded coronary arteries is limited by a restenosis/reocclusion rate of 50-70%. In patients with subtotal occlusion, stent implantation has been shown to reduce clinical and angiographic restenosis. Retrospective observational studies have suggested that stenting could reduce restenosis in total occlusions. The value of sustained coronary patency on global and regional left ventricular function in this clinical setting has not been defined clearly.
Objectives—To assess the medium term effect of elective intracoronary stent deployment after successful percutaneous transluminal coronary angioplasty (PTCA) of an occluded coronary artery.
Methods—Sixty patients with a total coronary occlusion successfully treated by PTCA were randomised to receive an intracoronary stent or no stent. Patients underwent clinical and angiographic follow up at six months.
Results—Thirty patients received a stent (group A) and 30 were treated by angioplasty alone (group B), all with initial success. One patient in group B required repeat angioplasty with stenting at 24 hours and one patient died after 10 days. Angiographic follow up was available for 57 patients. This showed a significantly reduced reocclusion rate in group A compared with group B (7% v 29%, p < 0.01) and a tendency to a reduced restenosis rate (22% v 40%, p = 0.105) in patients with no reocclusion. Left ventricular function, both global and regional, improved in group A. Only the regional left ventricular function in the area supplied by the target coronary artery improved in group B. Recurrence of symptoms and clinical events such as repeat angioplasty, coronary artery bypass grafting, death or myocardial infarction tended to be reduced in group A (4 (13%) v 9 (30%)).
Conclusions—Intracoronary stent insertion is effective in reducing the rate of reocclusion and shows a trend towards reduced restenosis after opening of a total coronary occlusion by balloon angioplasty. Sustained patency of the target coronary artery is associated with improvement in global and regional left ventricular function.

Keywords: intracoronary stenting;  total coronary occlusion;  left ventricular function     

Restenosis after elective coronary balloon angioplasty in patients with end stage renal disease: a case-control study using quantitative coronary angiography

Objective—To assess the rate of angiographic restenosis in patients with end stage renal disease after elective coronary angioplasty.
Design—A retrospective case-control study of 20 patients with end stage renal disease and 20 sex and age matched controls without renal disease, who had undergone primarily successful coronary angioplasty. Control coronary angiography was performed regardless of worsening or renewed incidence of anginal symptoms.
Main outcome measures—Group comparison of coronary morphology, as evaluated by quantitative coronary angiography, and of cardiovascular risk factors.
Results—The rate of angiographic restenosis was 60% in patients with renal disease and 35% in controls. In patients with end stage renal disease the following differences (mean (SD) were found versus controls: raised plasma fibrinogen (483 (101) v 326 (62) mg/dl, p < 0.001); raised plasma triglyceride (269 (163) v 207 (176) mg/dl, p < 0.01); smaller diameter of the coronary reference segment (2.59 (0.87) v 2.90 (0.55) mm, p < 0.10); smaller minimum luminal diameter of the dilated stenosis (0.77 (0.46) v 0.97 (0.27) mm, p < 0.05). Discriminant analysis showed that minimum luminal diameter before angioplasty (r = −0.79) and fibrinogen (r = +0.34) had the highest statistical association with restenosis.
Conclusions—The high rate of angiographic restenosis in patients with end stage renal disease seems to be related to the size of the vessel dilated and to an increased prothrombotic risk, as indicated by higher fibrinogen concentrations.

Keywords: renal disease;  coronary artery disease;  coronary angioplasty;  restenosis     

Clinical and angiographic outcome in patients with in-stent restenosis and repeat target lesion revascularisation in small coronary arteries

OBJECTIVE—To evaluate the clinical and angiographic outcome in patients with in-stent restenosis in small coronary arteries and repeat target lesion revascularisation.
DESIGN—Patients with in-stent restenosis in coronary arteries  2.85 mm were eligible for the study and underwent target lesion revascularisation. Clinical and angiographic variables were assessed during a six month follow up period.
RESULTS—73 patients with 79 lesions were treated by percutaneous transluminal coronary angioplasty (47%), excimer laser angioplasty (25%), or restenting (28%). The mean (SD) reference diameter before target lesion revascularisation was 2.12 (0.5) mm. Procedural success was achieved in all cases, but 57% of the patients had restenosis after six months. The rate of further restenosis was higher with laser angioplasty (78%) than with restenting (47%) or balloon angioplasty alone (49%, p < 0.05).
CONCLUSIONS—Treatment for in-stent restenosis in small coronary arteries is feasible and safe, with a second restenosis rate comparable to large coronary artery series. The strategy of target lesion revascularisation influences further in-stent restenosis, with an increased rate with laser angioplasty compared with restenting and repeat dilatation alone.


Keywords: restenosis; coronary stent; small vessels; coronary artery disease     

Long term outcome and cost-effectiveness of stenting versus balloon angioplasty for acute myocardial infarction

OBJECTIVE—To investigate the long term clinical outcome and cost-effectiveness of stenting compared with balloon angioplasty in patients with acute myocardial infarction.
METHODS—Patients with acute myocardial infarction were randomly allocated to primary stenting (112) or balloon angioplasty (115). The primary end point was the cumulative first event rate of death, non-fatal reinfarction, or target vessel revascularisation. Secondary end points were restenosis at six months and the cost-effectiveness at follow up.
RESULTS—After 24 months, the combined clinical end point of death/reinfarction was 4% after stenting and 11% after balloon angioplasty (p = 0.04). Subsequent target vessel revascularisation was necessary in 15 patients (13%) after stenting and in 39 (34%) after balloon angioplasty (p < 0.001). The cumulative cardiac event-free survival rate was also higher after stenting (84% v 62%, p < 0.001). The angiographic restenosis rate after stenting was less than after balloon angioplasty (12% v 34%, p < 0.001). Despite the higher initial costs of stenting (Dfl 21 484 v Dfl 18 625, p < 0.001), the cumulative costs at 24 months were comparable with those of balloon angioplasty (Dfl 31 423 v Dfl 32 933, p = 0.83).
CONCLUSIONS—Compared with balloon angioplasty, primary stenting for acute myocardial infarction results in a better long term clinical outcome without increased cost.


Keywords: stenting; angioplasty; myocardial infarction; cost-benefit analysis     

Randomised comparison of coronary stenting with and without balloon predilatation in selected patients

BACKGROUND—The SWIBAP (stent without balloon predilatation) prospective randomised trial was designed to compare direct coronary stenting with stenting preceded by lesion predilatation with an angioplasty balloon.
OBJECTIVE—To determine the feasibility and safety of direct stenting in non-complex coronary lesions in a prospective study.
PATIENTS AND DESIGN—All patients < 76 years of age scheduled to undergo angioplasty of a non-complex, non-calcified lesion in a coronary artery of > 3.0 mm, who granted their informed consent, were randomised into the trial. In group I, the stent was placed without balloon predilatation, while in group II stent implantation was preceded by balloon predilatation. The primary end point was the angiographic result according to procedure assigned by randomisation. An intravascular ultrasound substudy was performed in 60 patients.
RESULTS—Stent implantation was successful without predilatation in 192 of the 197 group I patients (97.5%), and with predilatation in 197 of the 199 group II patients (99%) (NS). No in-hospital stent thrombosis or death occurred. Overall procedural times, fluoroscopy times, and volumes of contrast agent given (mean (SD)) in group I v group II were 23.50 (13.54) min v 27.96 (15.23) min (p = 0.002), 6.04 (4.13) min v 6.67 (3.65) min (NS), and 135 (65) ml v 157 (62) ml (p < 0.001), respectively. No major adverse cardiovascular events had occurred by 30 days.
CONCLUSIONS—The feasibility and safety of direct stenting of selected and non-complex coronary lesions is confirmed. This technique was as successful as the conventional approach and was associated with a minor reduction in fluoroscopic exposure and procedure time and the administration of less contrast agent.


Keywords: coronary artery angioplasty; stent; coronary artery ultrasound     

Uncomplicated moderate coronary artery dissections after balloon angioplasty: good outcome without stenting

OBJECTIVE—To study the relation between moderate coronary dissections, coronary flow velocity reserve (CFVR), and long term outcome.
METHODS—523 patients undergoing balloon angioplasty and sequential intracoronary Doppler measurements were examined as part of the DEBATE II trial (Doppler endpoints balloon angioplasty trial Europe). After successful balloon angioplasty, patients were randomised to stenting or no further treatment. Dissections were graded at the core laboratory by two observers and divided into four categories: none, mild (type A-B), moderate (type C), severe (types D to F). Patients with severe dissections (n = 128) or without available reference vessel CFVR (n = 139) were excluded. The remaining 256 patients were divided into two groups according to the presence (group A, n = 45) or absence (group B, n = 211) of moderate dissection.
RESULTS—Following balloon angioplasty, there was no difference in CFVR between the two groups. At 12 months follow up, a higher rate of major adverse cardiac events was observed overall in group A than in group B (10 (22%) v 23 (11%), p = 0.041). However, the risk of major adverse events was similar in the subgroups receiving balloon angioplasty (group A, 6 (19%) v group B, 16 (16%), NS). Among group A patients, the adverse events risk was greater in those randomised to stenting (odds ratios 6.603 v 1.197, p = 0.046), whereas there was no difference in risk if the group was analysed according to whether the CFVR was < 2.5 or  2.5 after balloon angioplasty.
CONCLUSIONS—Moderate dissections left untreated result in no increased risk of major adverse cardiac events. Additional stenting does not improve the long term outcome.


Keywords: coronary dissection; intracoronary Doppler; angioplasty     

Early and intermediate term clinical outcome after multiple coronary stenting

Objective—To examine the immediate and intermediate term clinical outcome of multiple coronary stenting.
Design—Consecutive patients were prospectively entered on a dedicated database. Follow up information was obtained from outpatient and telephone interviews with patients and family physicians.
Setting—A tertiary referral centre.
Patients—140 consecutive patients underwent multiple coronary stenting between April 1994 and November 1996. Most patients had unstable coronary syndromes.
Main outcome measures—Death, cerebrovascular accidents, myocardial infarction (MI), coronary artery bypass surgery (CABG), and repeat angioplasty (PTCA).
Results—The angiographic success rate was 100% and the clinical procedural success rate 93%. The mean (SD) follow up was 11.9 (7.2) months (range 2-32). The mean (SD) number of stents per patient was 2.4 (0.7). The mean (SD) number of lesions treated per patient was 1.4 (0.6). There were four in-hospital deaths (2.9%) and five patients (3.6%) had an MI before hospital discharge. All in-hospital deaths occurred in patients presenting with an acute MI and cardiogenic shock. Three patients (2.2%) had a late MI. One patient with stent thrombosis underwent emergency CABG. Three patients (2.2%) underwent late CABG. Eight patients (5.7%) had a repeat PTCA. Eighty three patients (61.5%) were asymptomatic at follow up and 121 (86.4%) were free from major clinical events.
Conclusion—In an era of increased operator experience, high pressure stent deployment, and reduced anticoagulation with antiplatelet treatment alone, multiple coronary stenting may be performed with a high procedural success rate and good intermediate term outcome.

Keywords: angioplasty;  stents;  clinical outcome;  interventional cardiology     

Does primary stenting preserve cardiac function in myocardial infarction? A case-control study

OBJECTIVE—To investigate whether coronary stenting limits myocardial injury and preserves left ventricular function.
DESIGN AND SETTING—Prospective multicentre case-control study of primary percutaneous transluminal coronary angioplasty (PTCA) with and without stenting, performed in seven cardiovascular centres.
SUBJECTS AND METHODS—45 consecutive patients with acute myocardial infarction who were treated with successful primary stenting (Stent group) and did not have restenosis were paired with 45 matched control subjects with acute myocardial infarction treated by successful primary PTCA without stenting, also with no restenosis (POBA group).
RESULTS—In comparison with the POBA group, the Stent group—especially those patients with a left anterior descending coronary artery lesion—had a smaller hypokinesis area (mean (SD): 15.1 (20.0) v 34.4 (24.3) chords), reduced hypokinesis area/risk area (25.2 (31.9)% v 58.8 (40.1)%), and a larger ejection fraction (63.3 (10.2)% v 51.7 (11.7)%) evaluated by quantitative left ventriculography using the centreline method. In the Stent group, the correlation between risk area and hypokinesis area was significantly shifted downward. Multiple logistic regression analysis on infarct size limitation (hypokinesis area/risk area < 50%) identified preinfarction angina in all subjects and preinfarction angina and stenting in patients with left anterior descending coronary artery leasions as explanatory factors.
CONCLUSIONS—Primary PTCA using a coronary stent is effective in preventing myocardial injury and restoring left ventricular function in patients with anterior acute myocardial infarction.


Keywords: acute myocardial infarction; primary stenting; left ventricular function; preinfarction angina     

Endoluminal vessel reconstruction by stent placement in patients with obstructive coronary artery disease who are poor surgical candidates

Objective—To investigate the safety and efficacy of endoluminal vessel reconstruction by intracoronary stenting in patients with single or multivessel disease who have been turned down for surgical revascularisation.
Design—An observational, single centre trial of consecutive patients being followed up clinically.
Setting—Tertiary referral centre.
Patients—43 patients treated between 1995 and 1996 with a clinical follow up period of at least six months.
Main outcome measures—Acute procedural success following intervention (defined as a residual stenosis of < 30% with normal antegrade flow and without acute clinical complications); major adverse clinical events (death, myocardial infarction, repeat intervention, clinical restenosis); and functional status during follow up.
Results—Acute procedural success was achieved in 39 patients. Failures resulted from a refractory no reflow phenomenon with Q wave myocardial infarction (two patients), and from subacute stent thrombosis (one patient) and saphenous vein graft rupture at stent site (one patient), both manifesting by non-Q wave myocardial infarction. During a follow up period of 17 (8) months (mean (SD)), three of these patients died. Clinical restenosis was treated by repeat percutaneous intervention in 11 patients, while 28 patients remained asymptomatic. On a Kaplan-Meier estimate, the proportion of patients without adverse clinical events at two years was 65%.
Conclusions—Percutaneous reconstruction of diseased coronary arteries in patients with single or multivessel disease turned down for surgical revascularisation may be considered as a valuable treatment option. On follow up, more events seem to be encountered than after elective de novo stenting of discrete coronary lesions. This is probably related to higher clinical restenosis rates.

Keywords: coronary artery disease;  stents;  restenosis     

Interleukin 6 expression in coronary circulation after coronary angioplasty as a risk factor for restenosis

OBJECTIVE—To investigate changes in cytokine expression in the coronary circulation induced by percutaneous transluminal coronary angioplasty (PTCA).
METHODS—The study involved 32 patients with ischaemic heart disease who underwent elective PTCA for isolated stenotic lesions of the left coronary artery. Ten patients had plain old balloon angioplasty, 10 had percutaneous transluminal rotational atherectomy, and 12 had stent implantation. Blood samples were drawn from the coronary sinus before and immediately after PTCA. Plasma concentrations of interleukin 6 (IL-6), platelet derived growth factor (PDGF), monocyte chemoattractant protein 1 (MCP-1), and macrophage coronary stimulating factor (M-CSF) were measured. The patients were scheduled for follow up angiography six months after PTCA. Late loss index was calculated using quantitative coronary angiography.
RESULTS—IL-6 concentrations in coronary sinus blood increased immediately after PTCA (p < 0.001), but there was no change in PDGF, MCP-1, or M-CSF. There was a positive correlation between changes in IL-6 concentrations immediately after PTCA and late loss index six months after PTCA (r = 0.73, p < 0.001). IL-6 concentrations in coronary sinus blood were higher in patients with late restenosis than in those without restenosis (p < 0.001).
CONCLUSIONS—PTCA induces IL-6 production in the coronary circulation. This may induce subsequent inflammatory responses in injured vessels and play an important role in late restenosis after PTCA.


Keywords: inflammation; cytokine; restenosis     

Influence of a history of smoking on short term (six month) clinical and angiographic outcome after successful coronary angioplasty

OBJECTIVES—To assess the influence of smoking on restenosis after coronary angioplasty.
DESIGN AND PATIENTS—The incidence of smoking on restenosis was investigated in 2948 patients. They were prospectively enrolled in four major restenosis trials in which quantitative angiography was used before and immediately after successful angioplasty and again at six months.
RESULTS—Within the study population there were 530 current smokers, 1690 ex-smokers, and 728 non-smokers. Smokers were more likely to be men (85.9% v 87.5% v 65.3%, current v ex- v non-, p < 0.001), to be younger (54.0 (9.0) v 57.0 (9.1) v 59.9 (9.4) years, p < 0.001), to have peripheral vascular disease (7.2% v 5.5% v 2.3%, p < 0.001), and have sustained a previous myocardial infarction (42.9% v 43.9% v 37.9%, p = 0.022), but were less likely to be diabetic (9.1% v 9.5% v 12.6%, p = 0.043) or hypertensive (24.9% v 29.3% v 37.2, p < 0.001). There was no significant difference in the categorical restenosis rate (> 50% diameter stenosis) at six months (35.28% v 35.33% v 37.09%, current v ex- v non-), or the absolute loss (0.29 (0.54) v 0.33 (0.52) v 0.35 (0.55) mm, respectively; p = 0.172).
CONCLUSIONS—Although smokers have a lower incidence of known predisposing risk factors for atherosclerosis, they require coronary intervention almost six years earlier than non-smokers and three years earlier than ex-smokers. Once they undergo successful coronary angioplasty, there appears to be no evidence that smoking influences their short term (six month) outcome, but because of the known long term effects of smoking, patients should still be encouraged to discontinue the habit.


Keywords: coronary angioplasty; smoking; restenosis; quantitative angiography     

Is provisional stenting the effective option? The WIDEST study (Wiktor stent in de novo stenosis)

AIM—To compare the immediate and late outcomes of patients treated by a policy of routine stent implantation with routine balloon angioplasty and the use of stents only when an ideal result has not been obtained.
METHODS—A nine centre, multinational, randomised study of 300 patients with coronary artery disease thought suitable for treatment of a single lesion by balloon angioplasty or stent implantation. Only new lesions in patients who had not undergone previous bypass surgery were included, and totally occluded vessels were excluded.
RESULTS—The initial procedure was considered successful in 96% of patients. There was more complete angiographic restoration of luminal diameter in patients treated by elective stent (minimum lumen diameter (MLD) 2.68 mm for stent v 2.27 mm for balloon; p < 0.007), but analysis of the subgroup of balloon angioplasty patients who crossed over to stenting showed that they achieved similar results to the elective stent group. Late luminal loss was greater in stented patients than in those undergoing balloon angioplasty only, and by six months the angiographic benefit of stenting had disappeared (MLD 1.90 mm for stent group v 2.00 mm for balloon angioplasty). Angiographic and clinical results in the balloon angioplasty group were assisted by the high crossover rate (30.1%). Both groups had similar symptom relief, with 58.9% of patients improving by two or more angina grades. The need for further revascularisation was also similar in the two groups at one year (18.2% in the stented group v 17.1% in the balloon angioplasty group). Haemorrhagic complications at the local arterial entry site were more common than expected and were distributed equally between the patients receiving full anticoagulation and those receiving antiplatelet treatment only. The results of both Wiktor stent placement and balloon angioplasty were similar to the findings in the stent group in previous randomised studies (Benestent II, STRESS).
CONCLUSIONS—Provisional stenting appears to offer the same longer term outcome as elective stenting in this selected group of patients. Improvement in the results of conventional balloon angioplasty in the past 10 years means that a policy of obtaining an ideal result without the use of stents appears to be practicable in many of these patients, with consequent cost savings.


Keywords: stent; balloon angioplasty; coronary angioplasty     

Clinical events following excimer laser angioplasty or balloon angioplasty for complex coronary lesions: subanalysis of a randomised trial

Objectives—To compare clinical outcome in patients with complex coronary lesions treated with either excimer laser coronary angioplasty (ELCA) or balloon angioplasty.
Patients and design—308 patients with stable angina and a coronary lesion of more than 10 mm in length were randomised to ELCA (151 patients, 158 lesions) or balloon angioplasty (157 patients, 167 lesions). The primary clinical end points were death, myocardial infarction, coronary bypass surgery, or repeated coronary angioplasty of the randomised segment during six months of follow up. Subanalysis was performed to identify a subgroup of patients with a beneficial clinical outcome following ELCA or balloon angioplasty.
Setting—Two university hospitals and one general hospital.
Results—There were no deaths. Myocardial infarction, coronary bypass surgery, and repeated angioplasty occurred in 4.6, 10.6, and 21.2%, respectively, of patients treated with ELCA compared with 5.7, 10.8, and 18.5%, respectively, of those treated with balloon angioplasty. ELCA did not yield a favourable clinical outcome in subgroups of patients with long (more than 20 mm) coronary lesions, calcified lesions, small diseased vessels (2.5 mm reference diameter), or total coronary occlusions. There was a worse clinical outcome in patients with tandem lesions treated with ELCA compared with balloon angioplasty (9/18 v 3/26 lesions; p = 0.01); while a trend towards an unfavourable clinical outcome was found in patients with vessels with a reference diameter of more than 2.5 mm (23/66 v 13/63 lesions, p = 0.07) and left circumflex coronary lesions (12/41 v 6/42 lesions, p = 0.08).
Conclusions—The findings indicate a worse clinical outcome in patients with lesions of more than 10 mm treated with ELCA compared with balloon angioplasty who have tandem coronary lesions and in those with vessels with a reference diameter of more than 2.5 mm and left circumflex coronary lesions.

Keywords: excimer laser angioplasty; laser assisted balloon angioplasty; balloon angioplasty; randomised trial; interventional cardiology     

Monocyte expression of tissue factor and adhesion molecules: the link with accelerated coronary artery disease in patients with chronic renal failure

Objective—To investigate the expression of monocyte tissue factor (MTF) and adhesion molecules in patients with chronic renal failure (CRF) and to look for any correlation with thrombin generation and Lp(a) lipoprotein.
Design—A study of MTF expression and adhesion molecules, prothrombin fragments 1+2 (PTf1+2), an index of thrombin generation, and lipoproteins in patients with CRF and in normal control subjects.
Background—Patients with end stage renal failure have an increased risk of coronary artery disease despite advances in therapy. Stimulated monocytes are potent activators of blood coagulation through the generation of MTF, which was recently implicated in the aetiology of acute coronary ischaemic syndromes.
Methods—MTF expression and adhesion molecules were measured in whole blood using immunofluorescence of monocytes labelled with anti-tissue factor antibody and CD11b and c by flow cytometry. PTf1+2 and Lp(a) lipoprotein in plasma were measured by enzyme linked immunosorbent assay (ELISA).
Patients—70 patients with CRF without documented coronary artery disease (30 patients with CRF undialysed, 20 patients undergoing chronic ambulatory peritoneal dialysis (CAPD), and 20 undergoing haemodialysis (HD)), together with 20 normal controls, were studied.
Results—The (mean (SD)) increased MTF of CRF (48.0 (29) v 33.3 (7.2) mesf unit/100 monocytes in controls, p = 0.04) was more pronounced in patients undergoing dialysis (HD 73.1 (32.8) (p < 0.003) and CAPD 62.8 (28.9) mesf unit/100 monocytes, p < 0.04). MTF activity showed a positive correlation with both PTf1+2 and serum creatinine (p < 0.003) but not with Lp(a) lipoprotein. Lp(a) lipoprotein was significantly increased in both dialysis groups compared with controls (p < 0.005) and non-dialysis CRF groups (p < 0.02). Monocyte adhesion molecule (CD11b) was significantly higher in all three CRF groups than in the controls (p = 0.006).
Conclusion—This study has demonstrated a hypercoagulable state in patients with CRF. This was especially pronounced in the dialysis patients. These findings provide a possible explanation for the increased cardiovascular and cerebrovascular morbidity and mortality in these patients.

Keywords: chronic renal failure; haemodialysis; continuous ambulatory dialysis; monocyte tissue factor; monocyte adhesion molecules; prothrombin; Lp(a) lipoprotein     

Hospital transfer for primary coronary angioplasty in high risk patients with acute myocardial infarction

OBJECTIVE—To investigate the feasibility, safety, and associated time delays of interhospital transfer in patients with acute myocardial infarction for primary percutaneous transluminal coronary angioplasty (PTCA).
DESIGN AND PATIENTS—Prospective observational study with group comparison in a single centre. 68 consecutive patients with acute myocardial infarction transferred for primary PTCA from other hospitals (group A) were compared with 78 patients admitted directly to the referral centre (group B).
MAIN OUTCOME MEASURES—Patient groups were analysed with regard to baseline characteristics, time intervals from onset of chest pain to balloon angioplasty, hospital stay, and follow up outcome.
RESULTS—Patients in group A presented with a higher rate of cardiogenic shock initially than patients in group B (25% v 6%, p = 0.01) and had been resuscitated more frequently before PTCA (22% v 5%, p = 0.01). No deaths or other serious complications occurred during interhospital transfer. Median transfer time was 63 (range 40-115) minutes for helicopter transport (median 42 (28-122) km, n = 14), and 50 (18-110) minutes by ground ambulance (median 8 (5-68) km, n = 54). The median time interval from the decision to perform coronary arteriography to balloon inflation was 96 (45-243) minutes in group A and 52 (17-214) minutes in group B (p = 0.0001). In transferred patients (group A) the transportation associated delay and the longer in-hospital median decision time (50 (10-1120) minutes in group A v 15 (0-210) minutes in group B, p = 0.002) concurred with a longer total period of ischaemia (239 (114-1307) minutes in group A v 182 (75-1025) minutes in group B, p = 0.02) since the beginning of chest pain. Success of PTCA (TIMI 3 flow in 95% of all patients), in-hospital mortality (7% v 9%, mortality for patients not in cardiogenic shock 0% v 4%), and follow up after median 235 days was similarly favourable in groups A and B, respectively. Only one hospital survivor (group A) died during follow up.
CONCLUSION—Interhospital transport for primary PTCA in high risk patients with acute myocardial infarction is safe and feasible within a reasonable period of time. Short and medium term outcome is favourable. Optimising the decision process and transport logistics may further improve outcome by reducing the total time of ischaemia.


Keywords: acute myocardial infarction; primary percutaneous transluminal coronary angioplasty; hospital transfer; time delay     

Effect of stenting on coronary flow velocity reserve: comparison of coil and tubular stents

OBJECTIVE—To determine whether coil stents are as effective as tubular stents in improving coronary flow velocity reserve (CFVR) after stent deployment.
METHODS—Distal CFVR was measured with a 0.014 inch Doppler guide wire before and after stenting in 33 patients. A coil stent was implanted in 16 patients and a tubular stent was used in 17 patients. Coronary flow velocity within the stent was also recorded during a slow pullback.
RESULTS—Following placement of the stents, the percentage diameter stenosis was similar for both the tubular and coil stents (mean (SE) 11 (2)% v 13 (2)%, NS). However, distal CFVR was higher after stenting with a tubular stent compared with a coil stent (2.46 (0.13) v 1.96 (0.14), p < 0.05). Furthermore, pullback through the stent detected a major flow velocity increase within coil stents but not in tubular stents (83 (24)% v 5 (5)%, p < 0.05).
CONCLUSIONS—In spite of similar angiographic improvement, placement of coil stents was associated with inferior functional results compared with tubular stents. The flow velocity acceleration within the coil stents suggests the presence of a residual narrowing within the stent, which is not appreciated on angiography.


Keywords: stents; coronary flow reserve; Doppler guide wires     

Low dose dobutamine echocardiography for predicting functional recovery after coronary revascularisation

OBJECTIVE—To evaluate the effects of chronic coronary occlusion on the accuracy of low dose dobutamine echocardiography in predicting recovery of dysfunctional myocardium after revascularisation.
DESIGN—Retrospective study.
SETTING—Tertiary referral centre.
PATIENTS—53 consecutive patients with  70% stenosis of the left anterior descending coronary artery (LAD) and regional ventricular dysfunction (group 1, non-occluded LAD; group 2, occluded LAD) who underwent dobutamine echocardiography.
INTERVENTIONS—26 patients underwent coronary artery bypass grafting and 27 had percutaneous transluminal coronary angioplasty.
MAIN OUTCOME MEASURES—Baseline studies before revascularisation included cross sectional echocardiography at rest and during dobutamine infusion (5-10 µg/kg/min), and coronary angiography. The dobutamine study was performed mean (SD) 35 (28) days before revascularisation. Echocardiography at rest was repeated 90 (48) days after revascularisation.
RESULTS—Of 296 dysfunctional segments, 63 in group 1 (43%; 63/146) and 69 in group 2 (46%; 69/150) (NS) improved at follow up. Mean (SD) regional wall motion score index decreased from 1.97 (0.48) (95% confidence interval (CI) 1.01 to 2.93) before revascularisation to 1.74 (0.52) (95% CI 0.70 to 2.78) at follow up in group 1 (p = 0.001), and from 2.12 (0.41) (95% CI 1.30 to 2.98) to 1.88 (0.36) (95% CI 1.16 to 2.60) in group 2 (p = 0.0006). In group 1, sensitivity (87% v 52%; p < 0.0001), negative predictive value (88% v 65%; p = 0.001), and accuracy (77% v 64%; p = 0.01) were all significantly higher than in group 2, despite the angiographic evidence of collaterals in patients with occluded vessels.
CONCLUSIONS—Dobutamine echocardiography shows reduced sensitivity in predicting recovery of dysfunctional myocardium supplied by totally occluded vessels. Thus caution should be used in selecting such patients for revascularisation on the basis of a viability assessment made in this way.


Keywords: dobutamine; coronary artery disease; viability; chronic occlusion     

Interleukin 1 receptor antagonist gene polymorphism and restenosis after coronary angioplasty

BACKGROUND—Percutaneous transluminal coronary angioplasty (PTCA) is limited by the recurrence of luminal stenosis, which occurs in up to 50% of procedures. It has been shown that patient specific factors, perhaps genes, contribute to this process.
OBJECTIVE—To determine whether completion of healing after PTCA is part of an acute self limiting inflammatory process and whether polymorphism at important inflammatory gene loci might determine susceptibility to restenosis after PTCA.
DESIGN—DNA samples were collected from 171 patients attending for elective PTCA in Sheffield (S) and Leicester (L), who were scheduled to undergo follow up angiography (at four months (L) or six months (S)) as part of other restenosis studies. At follow up angiography, the patients were separated into restenosers (> 50% luminal narrowing) and non-restenosers (< 50% luminal narrowing). Four DNA polymorphisms within interleukin 1 (IL-1) related loci (IL-1A (−889), IL-1B (−511), IL-1B (+3954), and IL-1RN intron 2 VNTR (variable number tandem repeat)) were genotyped using methods based on polymerase chain reaction. Significance was assessed by χ² analysis of the relevant contingency table, and the magnitude of effect was estimated by calculating odds ratios. The Mantel-Haenszel (MH) test was applied to summarise data across the two populations.
RESULTS—Allele 2 at IL-1RN (IL-1RN*2) was significantly over represented in the non-restenoser group (L+S, 34% v 23% in restenosers). Furthermore, IL-1RN*2 homozygosity was increased in the non-restenoser population compared with the restenosers (MH test: p = 0.0196 (L+S); p = 0.031 (L+S, single vessel disease only), and the effect seemed to be restricted to the single vessel disease subpopulation. For other polymorphism within IL-1 related loci no significant associations were found with either restenosis or non-restenosis.
CONCLUSIONS—IL-1RN*2 may be associated with protection from restenosis after PTCA for individuals with single vessel disease. As this polymorphism has functional significance, this finding suggests that alteration in an individual's inflammatory predisposition may modulate the blood vessel response to injury.


Keywords: restenosis; inflammation; angioplasty; interleukin-1 receptor antagonist     

Three dimensional intravascular ultrasonic assessment of the local mechanism of restenosis after balloon angioplasty

OBJECTIVE—To assess the mechanism of restenosis after balloon angioplasty.
DESIGN—Prospective study.
PATIENTS—13 patients treated with balloon angioplasty.
INTERVENTIONS—111 coronary subsegments (2 mm each) were analysed after balloon angioplasty and at a six month follow up using three dimensional intravascular ultrasound (IVUS).
MAIN OUTCOME MEASURES—Qualitative and quantitative IVUS analysis. Total vessel (external elastic membrane), plaque, and lumen volume were measured in each 2 mm subsegment. Delta values were calculated (follow up − postprocedure). Remodelling was defined as any (positive or negative) change in total vessel volume.
RESULTS—Positive remodelling was observed in 52 subsegments while negative remodelling occurred in 44. Remodelling, plaque type, and dissection were heterogeneously distributed along the coronary segments. Plaque composition was not associated with changes in IVUS indices, whereas dissected subsegments had a greater increase in total vessel volume than those without dissection (1.7 mm³ v −0.33 mm³, p = 0.04). Change in total vessel volume was correlated with changes in lumen (p < 0.05, r = 0.56) and plaque volumes (p < 0.05, r = 0.64). The site with maximum lumen loss was not the same site as the minimum lumen area at follow up in the majority (n = 10) of the vessels. In the multivariate model, residual plaque burden had an influence on negative remodelling (p = 0.001, 95% confidence interval (CI) −0.391 to −0.108), whereas dissection had an effect on total vessel increase (p = 0.002, 95% CI 1.168 to 4.969).
CONCLUSIONS—The mechanism of lumen renarrowing after balloon angioplasty appears to be determined by unfavourable remodelling. However, different patterns of remodelling may occur in individual injured coronary segments, which highlights the complexity and influence of local factors in the restenotic process.


Keywords: balloon angioplasty; intravascular ultrasound; remodelling; restenosis     

Endogenous endothelin maintains coronary artery tone by endothelin type A receptor stimulation in patients undergoing coronary arteriography

OBJECTIVE—To examine the contribution of endothelin type A (ET_A) receptor stimulation by endogenously generated endothelin-1 (ET-1) to the maintenance of coronary vascular tone in humans.
DESIGN—Controlled clinical study.
SETTING—Tertiary cardiovascular referral centre.
PATIENTS—14 subjects were studied, seven with normal coronary arteries and seven with coronary artery disease, mean (SEM) age, 53 (2) years.
INTERVENTIONS—After diagnostic coronary arteriography, BQ-123 (a selective ET_A receptor antagonist; 100 nmol/min) in 0.9% saline, was infused into the left coronary artery at a rate of 1 ml/min for 60 minutes. Eight control subjects received saline alone.
MAIN OUTCOME MEASURES—Blood flow velocity in the left anterior descending coronary artery, measured using a Doppler flow guidewire; coronary arteriography performed at baseline and immediately at the end of the BQ-123 or saline infusion to measure the diameter of proximal and distal left anterior descending coronary artery segments.
RESULTS—The diameter of the proximal segment increased by 6 (2)%, while that of the distal segment increased by 12 (3)% after BQ-123 (both p < 0.05 v baseline). Coronary blood flow increased from 75 (10) to 92 (10) ml/min and coronary vascular resistance decreased from 1.99 (0.36) to 1.44 (0.22) mm Hg/ml/min after BQ-123 (both p < 0.05 v baseline). The response to BQ-123 of patients with and without coronary artery disease was similar. There was no effect of saline in the controls.
CONCLUSIONS—Endogenously produced ET-1 contributes to the maintenance of basal coronary artery tone in humans by ET_A receptor stimulation. The role of ET_B receptors remains to be defined.


Keywords: endothelins; arteries; blood flow; coronary circulation; angiography