Change in diameter of coronary artery segments adjacent to stenosis after percutaneous transluminal coronary angioplasty: failure of percent diameter stenosis measurement to reflect morphologic changes induced by balloon dilation.

To determine the changes in stenotic and nonstenotic segments of a dilated coronary artery, detailed quantitative angiographic measurements were performed in 342 patients (398 lesions) immediately after angioplasty and at a predetermined follow-up time of 30, 60, 90 or 120 days after the dilation. Measurements of the stenotic segments were expressed as minimal luminal diameter, and the adjacent nonstenotic segments were expressed as interpolated reference diameter (both in millimeters). A follow-up rate of 86% was achieved. In the patients followed up at 30 and 60 days, there was no significant change in either the mean minimal luminal diameter or the mean reference diameter. However, at 90 and 120 days, there was significant deterioration in both the mean minimal luminal diameter (-0.37 and -0.42 mm, respectively) and the mean reference diameter (-0.17 and -0.26 mm, respectively), all of the changes being highly significant (p less than 0.00001). The reference diameter is involved in the dilation process and may be subject to the same restenosis process that takes place in initially stenotic segments. Percent diameter stenosis measurements, which are conventionally used to express the change in the severity of a stenosis after angioplasty, will tend to underestimate the change when there is a simultaneous reduction in the reference diameter.

Assessment of "silent" restenosis and long-term follow-up after successful angioplasty in single vessel coronary artery disease: the value of quantitative exercise electrocardiography and quantitative coronary angiography.

Exercise electrocardiographic (ECG) testing during follow-up after coronary angioplasty is widely applied to evaluate the efficacy of angioplasty, even in asymptomatic patients. One hundred forty-one asymptomatic patients without previous myocardial infarction underwent quantitative exercise ECG testing and quantitative coronary angiography 1 to 6 months after successful angioplasty in single vessel coronary artery disease to 1) determine the value of exercise ECG testing to detect "silent" restenosis, and 2) assess the long-term prognostic value of exercise ECG testing and coronary angiography. The prevalence of restenosis (defined as greater than or equal to 50% luminal narrowing at the dilation site) was 12% in this selected study group. Of 26 patients with an abnormal exercise ECG (ST segment depression greater than or equal to 0.1 mV), only 4 (15%) showed recurrence of stenosis. Sensitivity and specificity for detection of restenosis were 24% and 82%, respectively. One hundred thirty-four patients (95%) were followed up 1 to 64 months (mean 35) after exercise ECG testing and coronary angiography. Thirty-two patients (24%) experienced a cardiac event: in 25 patients (78%) the initial event was recurrent angina pectoris (New York Heart Association class III or IV) and in 7 patients (22%) it was myocardial infarction, although cardiac death did not occur. The mean interval between exercise ECG testing and the initial cardiac events was 14 months (range 1 to 55), whereas 47% of the initial events took place less than or equal to 6 months after exercise ECG testing.(ABSTRACT TRUNCATED AT 250 WORDS)

Restenosis after coronary angioplasty: the paradox of increased lumen diameter and restenosis.

Restenosis after coronary angioplasty is the single complication that most limits this revascularization procedure in clinical practice. The process is largely unpredictable and the lesion-related factors predisposing to restenosis are poorly understood, with little consensus in published reports. In this study using detailed quantitative angiographic measurements to assess 490 lesions, the simple lesion characteristics associated with restenosis were defined and the relation to the restenosis process documented. Restenosis was defined as an absolute deterioration in the minimal lumen diameter by greater than or equal to 0.72 mm, a criterion based on the 95% confidence intervals for repeat angiographic measurements. This was chosen in an attempt to separate spurious changes due to a poor angiographic result and the variability of angiographic measurements from significant changes due to the restenosis process. The principal determinants of restenosis were found to be a large improvement in the minimal lumen diameter at the time of dilation (1.13 mm for the restenosis group compared with 0.86 mm for the no restenosis group [p less than 0.0001]) and an optimal postangioplasty result (minimal lumen diameter 2.28 mm in the restenosis group compared with 2.05 mm [p less than 0.001] in the no restenosis group, corresponding to a 25% and a 30% diameter stenosis, respectively [p less than 0.0001]). These observations reported for the first time suggest that the distinction needs to be made between a "clinical restenosis" of greater than or equal to 50% diameter stenosis and the "restenosis process" as measured by the absolute changes occurring during and after angioplasty.(ABSTRACT TRUNCATED AT 250 WORDS)

[Effects and chronology of coronary restenosis after percutaneous transluminal coronary angioplasty. Quantitative angiographic analysis at 1, 2, 3, 4 and 5 months]. / Incidence et chronologie de la resténose coronaire après angioplastie coronarienne transluminale percutanée. Analyse angiographique quantitative aux 1er, 2e, 3e, 4e et 5e mois.

Coronary restenosis occurs fairly early after transluminal coronary angioplasty, as suggested by anatomico-clinical, isotopic and angiographic studies. Its incidence, as reported in the literature, varies according to the clinical selection of patients, to the number of patients with follow-up angiography and the timing of this procedure, and to the criteria used to define restenosis. In this prospective study we endeavoured to determine the exact date at which restenosis takes place, as well as its true incidence, by means of 6 different angiographic criteria. The population studied was divided into five groups and each group underwent coronary arteriography at a different date: during the 1st, 2nd, 3rd, 4th and 5th post-angioplasty months respectively. In 424 of the 500 patients thus examined (84.8 p. 100), coronary angiography involved automatic detection of contours and made quantitative analysis possible. Coronary restenosis was found to occur early, with a peak of incidence in the 3rd month. Its incidence varied considerably depending on the criterion used. A critical analysis of the data has prompted us to use a criterion based on absolute values determined by quantitative angiographic analysis.

[Assessment of immediate geometric changes in coronary stenosis after implantation of stents by quantitative angiographic analysis]. / Appréciation des modifications géométriques immédiates de la sténose coronaire après implantation de tuteurs par analyse angiographique quantitative.

In order to assess the immediate geometric changes in coronary stenosis that occur after implantation of intra-coronary stents, a quantitative angiographic analysis (automatic delineation of contours) was performed in 18 patients. Following angioplasty, the implantation of a stent significantly increases the diameter and area of the stenotic segment in absolute values. This improvement is attended by a significant decrease in resistance and in the theoretical trans-stenotic pressure gradient. Beside its role as mechanical support of the dilated arterial wall, the stent possesses an intrinsic force of dilatation confirmed by the results of quantitative angiographic analysis.

[Chronology and incidence of restenosis after coronary angioplasty. Comparison of patients with stable and unstable angina]. / Chronologie et incidence de la resténose après angioplastie coronaire. Comparaison des patients présentant un angor stable à ceux présentant un angor instable.

The aim of this prospective study was to compare the incidence of restenosis after percutaneous transluminal coronary angioplasty (PTCA) in patients with stable and unstable angina before the procedure. Between January 1984 and February 1986, 344 patients with stable angina and 228 patients with unstable angina underwent PTCA. The primary success rate was 86.3 per cent in patients with stable angina (297 patients) and 87.7 per cent in patients with unstable angina (200 patients). The patients were recalled for systematic control coronary arteriography at 30, 60, 90, 120 or 150 days, and was obtained in 83.8 per cent of patients with stable angina and in 86 per cent of patients with unstable angina. The degree of stenosis before and the angiographic changes after PTCA and at control coronary arteriography were evaluated by a computer-assisted automatic contour detection system. The three criteria of restenosis were: 1) over 50 per cent loss of the benefit of PTCA, 2) residual post-PTCA stenosis increasing from less than 50 per cent to more than 50 per cent at control arteriography, 3) a decrease in the minimum intraluminal diameter of at least 0.72 mm with respect to the immediate post-PTCA result. A comparison between the two groups of patients showed that the average age was slightly greater in patients with unstable angina (56 +/- 9 years vs 58 +/- 9 years, p = 0.047). Apart from this difference, the two groups were comparable with regards to the average number of lesions dilated per patient, the date of control arteriography, the severity of the coronary artery disease and previous bypass surgery, angioplasty and infarction.(ABSTRACT TRUNCATED AT 250 WORDS)

Methods for the assessment of PTCA success.

Numerous criteria for the assessment of the immediate and late results of percutaneous transluminal coronary angioplasty (PTCA) are currently in use. Here, the values and limitations of the transstenotic gradient (TG), visual qualitative angiogram assessment, quantitative coronary angiography and the coronary flow reserve (CFR) will be discussed. Although measurement of the TG may be clinically useful, current data suggest that it does not accurately reflect the "true" pressure-flow-resistance across coronary lesions. Furthermore, the widely applied method of visual interpretation of coronary angiograms is hampered by several serious shortcomings: large intra- and interobserver variabilities, and lack of correlation with pathologic as well as intraoperative findings. In contradistinction, CFR and minimal luminal cross-sectional area (MLCA) appear to be more reliable parameters for judging the physiologic importance of (residual) coronary obstructions. In fact, given the curvilinear relation between CFR and MLCA (r = 0.92), the available evidence suggests that at the moment quantitative coronary angiography--with measurement of the MLCA immediately after PTCA--is the method of choice in assessing the efficacy of coronary angioplasty.

Angioplasty for stable versus unstable angina pectoris: are unstable patients more likely to get restenosis? A quantitative angiographic study in 339 consecutive patients.

Current evidence with regard to the possible association between clinical expression of coronary disease prior to the time of angioplasty, and the subsequent risk of restenosis following successful dilatation, remains inconclusive. To prospectively compare the incidence of restenosis in stable versus unstable angina pectoris patients, follow-up angiography was performed in 85 percent of patients from a consecutive series with a successful PTCA, irrespective of presence or absence of recurrent ischemic symptoms. Furthermore, changes in lesion severity were assessed quantitatively by an automated edge-detection technique rather than visual analysis. Employing such a study design and follow-up protocol, it was found that the incidence of restenosis in patients with stable coronary artery disease was similar to that of patients with unstable rest angina, irrespective of the type of angiographic definition used.

Long-acting coronary vasodilatory action of the molsidomine metabolite Sin 1: a quantitative angiographic study.

The vasodilatory action of molsidomine was studied by intracoronary injection of its active metabolite, Sin 1. In 10 patients repeat coronary angiography in multiple projections was performed before and 2 minutes after administration of 1 mg of Sin 1, and before and after a second injection 60 minutes later. Contours of obstructed and non-obstructed segments of the left coronary artery were quantitatively analysed with a computer-based angiography analysis system. Immediately after its administration, Sin 1 increased the mean diameters of 44 normal coronary segments by 12% (P less than 0.001). Significant vasodilation (8%) was still observed after 60 minutes. At that time, repeated administration of Sin 1 increased the vasodilation by an additional 14% with respect to the control situation. An increase in obstruction diameter was observed in 6 out of 8 obstructed segments. Mean increase in the minimal obstruction diameter was still 10% after 60 minutes.

Short-, medium-, and long-term follow-up after percutaneous transluminal coronary angioplasty for stable and unstable angina pectoris.

The first 840 consecutive patients who underwent percutaneous transluminal coronary angioplasty (PTCA) performed in the same institution were retrospectively assessed at an average follow-up period of 25 months after the initial procedure. The study population consisted of 506 patients with stable angina pectoris (group 1) and 334 patients with unstable angina pectoris (group 2). Clinical end points were death, nonfatal myocardial infarction, recurrent angina pectoris necessitating bypass surgery or repeat PTCA, and event-free survival. The two groups were comparable with respect to age, sex, previous myocardial infarction, ejection fraction, and number of diseased vessels. PTCA was successful in 83.0% of group 1 and 87.1% of group 2. Follow-up rates were expressed as events per attempted PTCA in a patient group. No difference in survival was observed between the two groups, the mortality rate being approximately 2.8% at 25 months. In the group with stable angina pectoris there was a lower incidence of nonfatal myocardial infarction within the first 24 hours after angioplasty; 4.3% vs 9.0% (p less than 0.01). During long-term follow-up the increase in the incidence of nonfatal myocardial infarction was similar, resulting in an overall long-term follow-up infarction rate of 8.3% and 14.2%, respectively (p less than 0.01). A higher event-free survival was observed in group 1 within 24 hours after PTCA: 93.7% vs 84.2% (p less than 0.01). During subsequent follow-up the difference in event-free survival between the two groups was no longer significant: 68.5% vs 61.2%.(ABSTRACT TRUNCATED AT 250 WORDS)

Incidence of restenosis after successful coronary angioplasty: a time-related phenomenon. A quantitative angiographic study in 342 consecutive patients at 1, 2, 3, and 4 months.

Data from experimental, clinical, and pathologic studies have suggested that the process of restenosis begins very early after coronary angioplasty. The present study was performed to determine prospectively the incidence of restenosis with use of the four National Heart, Lung, and Blood Institute and the 50% or greater diameter stenosis criteria, as well as a criterion based on a decrease of 0.72 mm or more in minimal luminal diameter. Patients were recatheterized at 30, 60, 90, or 120 days after successful percutaneous transluminal coronary angioplasty (PTCA). After PTCA all patients received 10 mg nifedipine three to six times a day and aspirin once a day until repeat angiography. Of 400 consecutive patients in whom PTCA was successful (less than 50% diameter stenosis), 342 underwent quantitative angiographic follow-up (86%) by use of an automated edge-detection technique. A wide variation in the incidence of restenosis was found dependent on the criterion applied. The incidence of restenosis proved to be progressive to at least the third month for all except NHLBI criterion II. At 4 months a further increase in the incidence of restenosis was observed when defined as a decrease of 0.72 mm or more in minimal luminal diameter, whereas the criteria based on percentage diameter stenosis showed a variable response. The lack of overlap between the different restenosis criteria applied affirms the arbitrary nature of angiographic definitions currently in use. Restenosis should be assessed by repeat angiography, and preferably ascertained according to the change in absolute quantitative measurements of the luminal diameter.

Percutaneous balloon valvuloplasty for calcific aortic stenosis. A treatment 'sine cure'?

Twenty-five elderly patients with calcific aortic stenosis, 12 male (48%) and 13 female (52%), mean age 74.8 +/- 7.6 years, underwent percutaneous aortic balloon valvuloplasty between March 1986 and September 1987. Twenty-two patients (88%) were in class III-IV of the New York Heart Association, 13 (52%) had a history of previous angina and 7 (28%) of syncopal attacks. All patients had been considered either unsuitable or high-risk candidates for aortic-valve replacement because of age or associated diseases. Balloons of increasing size (area ranging from 1.3 to 3.8 cm2 during inflation) were successively passed retrogradely from the femoral artery and manually inflated to 3-7 atmospheres. Inflation duration ranged from 15 to 260 s (mean 40 s). Post-dilatation there were significant changes in left ventricular peak-systolic and end-diastolic pressures (P less than 0.00001 and P less than 0.01, respectively), mean systolic aortic transvalvular gradient (from 73 to 43 mmHg, P less than 0.000001), mean systolic aortic flow (from 176 to 208 ml s-1, P less than 0.0001) and aortic valve area (from 0.47 to 0.72 cm2, P less than 0.000001). Major complications included: in-hospital deaths of two patients (8%) admitted in cardiogenic shock; left haemiplegia (4%); transient haemianopia (8%); development of grade III aortic insufficiency (4%); and persistent complete atrioventricular block (4%). Complications at the puncture-site occurred in 7 patients (28%)--including two femoral pseudoaneurysms and the need for surgical removal of a balloon remnant after rupture in one patient. No local haemorrhagic complications were observed in the latter eight procedures, performed using a 16.5 French 100-cm long arterial introducer. At a mean follow-up of 13.0 +/- 5.0 months, an important functional improvement persisted in 14 patients (56%), no major changes in pre-valvuloplasty symptoms were observed in 3 patients (12%), while five patients (20%) required surgical treatment after a successful valvuloplasty because of recurrence of symptoms (late valve restenosis). Percutaneous aortic balloon valvuloplasty is a possible palliative therapy in elderly patients with calcific aortic stenosis. However, its inherent immediate risk, limited haemodynamic result and the possible development of valve restenosis at medium-term follow-up, suggest that the application of this technique should be limited to poor surgical candidates.