Biomedical subjects

M R Bell

Publications and source records attributed to M R Bell.

At least 37 records · Page 2Linked to original sources

PubMed1999

Timing of coronary stent thrombosis in patients treated with ticlopidine and aspirin.

In patients receiving coronary stents treated with aspirin and coumadin, the peak incidence of stent thrombosis occurs on the fifth and sixth days following the implantation procedure. Little is known about the timing of stent thrombosis in patients treated with aspirin and ticlopidine. We compared the timing of coronary stent thrombosis in patients treated with ticlopidine and aspirin with the timing in those receiving coumadin and aspirin. A retrospective databank analysis was performed and 39 patients were identified who experienced stent thrombosis after successful coronary stent implantation. Of these, 21 had been treated with ticlopidine and aspirin and 18 with coumadin and aspirin therapy. The median time from stent implantation to stent thrombosis in the ticlopidine and aspirin group was 12 hours (interquartile range 6 to 72 hours) compared with 4 days in the coumadin and aspirin group (interquartile range 21 to 68 hours) (p <0.0001). There was no significant difference between the timing of stent thrombosis in patients treated with abciximab in addition to ticlopidine and aspirin (median 17 hours, interquartile range 6 to 29) versus ticlopidine and aspirin patients who did not receive abciximab (median 11 hours, interquartile range 9 to 12, p = 0.57). Thus, in patients who receive coronary stents, stent thrombosis occurs much earlier after the procedure in patients treated with ticlopidine and aspirin than in patients treated with anticoagulation therapy.

Angioplasty, Balloon, Coronary↗

PubMed1999

Safety and efficacy of ticlopidine for only 2 weeks after successful intracoronary stent placement.

BACKGROUND: In patients receiving intracoronary stents, stent thrombosis is reduced when ticlopidine therapy is combined with aspirin after the procedure. However, ticlopidine causes neutropenia in 1% of patients when administered for >2 weeks, and little is known about the duration that ticlopidine needs be administered to prevent stent thrombosis. METHODS AND RESULTS: We analyzed 827 patients undergoing successful stent placement in 1061 coronary segments at Mayo Clinic who were treated between May 1, 1996, and October 31, 1997. Chronic warfarin therapy, cardiogenic shock, and enrollment in research protocols requiring 4 weeks of ticlopidine were exclusion criteria; ticlopidine was discontinued after 14 days in all remaining patients. The mean age of the study population was 64+/-11 years; 49% had suffered a prior infarction, 20% had undergone coronary artery bypass surgery, and 65% had multivessel disease. The indication for stent placement was dissection or abrupt closure in 31% of patients and suboptimal results from balloon angioplasty in 18%. Placement was elective in 51% of patients, and 10.3% of patients were treated within 12 hours of an acute myocardial infarction. Mean nominal stent size was 3.3+/-0.5 mm. High-pressure inflations (>/=12 atm) were performed in all patients (mean, 17+/-4 atm). Intravascular ultrasound was used to facilitate stent placement in 8.8% of patients. Abciximab was administered to 38% of patients; 11% of patients who were at increased risk of stent thrombosis were treated with enoxaparin for 10 to 14 days. Adverse cardiovascular events in the 14 days after stent placement occurred in 11 patients (1.3%). Two patients died of nonischemic causes (sepsis and renal failure) in the 15th through 30th days after ticlopidine was stopped. However, there were no cardiovascular deaths, myocardial infarctions, coronary artery bypass operations, or repeat angioplasty procedures between the 15th and 30th days; stent thrombosis did not occur in any patient after ticlopidine had been stopped. No patient developed neutropenia, although 1.8% of the first 489 patients who were closely monitored for side effects from ticlopidine developed side effects requiring its discontinuation, and milder side effects occurred in 4.7%. CONCLUSIONS: In patients receiving intracoronary stents, the discontinuation of ticlopidine therapy 14 days after stent placement is associated with a very low frequency of stent thrombosis and other adverse events.

Abciximab↗

PubMed1999

Clinical, angiographic, and procedural correlates of abrupt vascular closure during coronary intervention: a 10-year experience at Mayo Clinic.

A large matched-cohort study was carried out to determine correlates of in-hospital abrupt vascular closure (AC). Univariate analysis identified current cigarette smoking (P = 0.021), myocardial infarction within 24 hr prior to procedure (P = 0.0035), emergency procedure (P = 0.02), lesion thrombus (P = 0.0001), and lesion angulation (P = 0.021) as significant clinical and angiographic variables. Relative to balloon angioplasty (PTCA), use of atherectomy (P = 0.015) and laser devices (P = 0.018) but not elective stent placement (P = 0.97) were associated with increased risk of AC. In the multivariate model, current cigarette smoking (P = 0.0474), lesion thrombus (P = 0.0001), lesion angulation (P = 0.0124), use of atherectomy devices (P = 0.001), and laser devices (P = 0.0037) remained as significant correlates of increased AC events. In conclusion, the risk of AC appears associated primarily with lesion characteristics and use of nonballoon devices other than stents. Elective stent placement did not appear to reduce AC risk over conventional PTCA; the small number of patients studied may have prevented any benefit from being observed.

Angioplasty, Balloon, Coronary↗

PubMed1999

Real-time measurement of radiation exposure to patients during diagnostic coronary angiography and percutaneous interventional procedures.

OBJECTIVES: The aim of this study was to accurately assess the radiation exposure received by patients during cardiac catheterization in a large sample representative of the current state of practice in cardiac angiography. BACKGROUND: Radiation exposure to patients and laboratory staff has been recognized as a necessary hazard in coronary angiography. The effects on x-ray exposure of the increased complexity of coronary angiographic procedures and, in particular, the increasing use of coronary artery stenting, have not been adequately addressed in previous studies. METHODS: X-ray exposure measurements were performed on a consecutive series of 972 patients undergoing 992 diagnostic and interventional studies in the Mayo Clinic catheterization laboratory within an eight week period in late 1997. Data were acquired from 706 diagnostic procedures and 286 interventional procedures using a real-time exposure measurement system to continuously calculate and record the exposure rate and total exposure, reflecting all parameters relevant to the specific patient and procedure situation. RESULTS: The median exposure for all 992 procedures was 41.8 mC/kg (162.1 R); the corresponding values for diagnostic and interventional procedures were 34.9 and 95.6 mC/kg, respectively (135.3 vs. 370.5 R). There were significant differences in the fluoroscopy exposure time between diagnostic and interventional procedures: 4.7 min vs. 21.0 min. Heavier patients (>83 kg) received x-ray exposures at a significantly higher rate than did lighter patients (<83 kg) during both fluoroscopy and cine; 44.9 mC/kg/min (173.9 R/min) vs. 27.9 mC/kg/min (108.3 R/min) for cine exposure rate and 2.3 mC/kg/min (8.8 R/min) vs. 1.5 mC/kg/min (5.8 R/min) for fluoroscopy exposure rate. CONCLUSIONS: Changes in practice have led to higher values for patient x-ray radiation exposures during cardiac catheterization procedures. The real-time display and recording of x-ray exposure facilitates the reduction of exposure in the catheterization laboratory.

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PubMed1999

Clopidogrel versus ticlopidine after intracoronary stent placement.

OBJECTIVES: The study compared the safety and efficacy of ticlopidine with clopidogrel in patients receiving coronary stents. BACKGROUND: Stent thrombosis is reduced when ticlopidine is administered with aspirin. Clopidogrel is similar to ticlopidine in chemical structure and function but has fewer side effects; few data are available about its use in stent patients. METHODS: We compared 30-day event rates in 500 consecutive coronary stent patients treated with aspirin and clopidogrel (300 mg loading dose immediately prior to stent placement, and 75 mg/day for 14 days) to 827 consecutive stent patients treated with aspirin and ticlopidine (500 mg loading dose and 250 mg twice daily for 14 days). RESULTS: Patients treated with clopidogrel had more adverse clinical characteristics including older age, more severe angina, and more frequent infarction within the prior 24 h. Nonetheless, mortality was 0.4% in clopidogrel patients versus 1.1% in ticlopidine patients; nonfatal myocardial infarction occurred in 0% versus 0.5%, stent thrombosis in 0.2% versus 0.7%, bypass surgery or repeat angioplasty in 0.4% versus 0.5%, and any event occurred in 0.8% versus 1.6% of patients, respectively (p = NS). Based on the observed 30-day event rate of 1.6% with ticlopidine, the statistical power of the study was 43% to detect an even rate of 0.5% with clopidogrel, and 75% to detect an event rate with of 4% with clopidogrel, with a p value of 0.05. CONCLUSIONS: These data indicate that clopidogrel can be safely substituted for ticlopidine in patients receiving coronary stents.

Aged↗

PubMed1999

Validation of minimally invasive measurement of myocardial perfusion using electron beam computed tomography and application in human volunteers.

OBJECTIVES: To measure myocardial perfusion using an estimate of intramyocardial vascular volume obtained by electron beam computed tomography (EBCT) in an animal model; to assess the feasibility and validity of measuring regional myocardial perfusion in human volunteers using the techniques developed and validated in the animal studies. METHODS: Measurements of myocardial perfusion with EBCT employing intravenous contrast injections were compared with radioactive microsphere measurements (flow 57 to 346 ml/100 g/min) in seven closed chest dogs. Fourteen human volunteers then underwent EBCT scans using intravenous contrast injections. RESULTS: Mean (SEM) global intramyocardial vascular volume by EBCT was 7.6 (1.1)%. The correlation between global EBCT (y) and microsphere (x) perfusion was y = 0.59x + 15.56 (r = 0.86) before, and y = 0.72x + 6. 06 (r = 0.88) after correcting for intramyocardial vascular volume. Regional perfusion correlation was y = 0.75x + 23.84 (r = 0.82). Corresponding improvements in agreement between the two techniques were also seen using Bland-Altman plots. In the human subjects, mean resting global myocardial flow was 98 (6) ml/100 g/min, with homogeneous flow across all regions. In 10 of these subjects, perfusion was studied during coronary vasodilatation using intravenous adenosine. Global flow increased from 93 (5) ml/100 g/min at rest to 250 (19) ml/100 g/min during adenosine (p < 0.001), with an average perfusion reserve ratio of 2.8 (0.2). Similar changes in regional perfusion were observed and were uniform throughout all regions, with a mean regional perfusion reserve ratio of 2.8 (0.3). CONCLUSIONS: Accounting for intramyocardial vascular volume improves the accuracy of EBCT measurements of myocardial perfusion when using intravenous contrast injections. The feasibility of providing accurate measurements of global and regional myocardial perfusion and perfusion reserve in people using this minimally invasive technique has also been demonstrated.

Adenosine↗

PubMed1999

Utility of bilateral coronary injections during complex coronary angioplasty.

We describe a technique useful in complex coronary interventions wherein timed bilateral contrast injections are given in both coronary arteries. This technique is useful in chronic total occlusions in which the distal coronary vessel is not visualized except by collateral filling via the contralateral artery. This technique was applied in 12 patients; 11 with native coronary occlusion and one in whom the target site was visualized by contrast injections into a vein graft supplying competitive flow to an otherwise patent native vessel. With this technique, the distal coronary artery segment can be better visualized, which helps to aim and track the guide wire across the occluded segment.

Aged↗

PubMed1998

Usefulness of abciximab for treatment of early coronary artery stent thrombosis.

The clinical and angiographic outcomes of 10 patients who received abciximab as part of their therapy for early stent thrombosis was compared with 25 patients (using historical controls) who received conventional therapy. Although the angiographic outcome and the incidence of myocardial infarction in both groups was similar, there were no deaths or referral for emergency coronary bypass surgery in the abciximab-treated group versus 3 deaths and 10 referrals for emergency bypass surgery in the conventionally treated group.

Abciximab↗

PubMed1998

Abciximab administration and outcome after intracoronary stent implantation.

Although adjunctive abciximab therapy improves outcome after angioplasty or atherectomy, there are few data demonstrating its benefit for intracoronary stent implantation. We characterized patients receiving abciximab for stent placement in our practice and determined the impact of abciximab on outcome. Abciximab was introduced to our practice in April 1995 for percutaneous revascularization. Demographic, clinical, and angiographic variables that were independently associated with the use of abciximab for stent placement through 1996 (abciximab era) were examined. We then examined among all patients receiving stents from 1992 through 1996 (preabciximab and abciximab eras) whether the use of abciximab was independently associated with improved outcome (death, nonfatal Q-wave myocardial infarction, coronary bypass surgery, or target vessel percutaneous revascularization) in the hospital and at 30 days. The 30-day event rate was 7% for those who did or did not receive abciximab. The following characteristics were independently associated with the use of abciximab for stent placement in the abciximab era: thrombus before stent placement (chi-square 50.5), > or =2 stents implanted (chi-square 10.8), stent in venous graft (chi-square 7.4), calcific lesion (chi-square 5.8), and hypertension (chi-square 5.5). Among all patients receiving stents in the preabciximab and abciximab eras (n=1,859), the presence of these characteristics was independently associated with worse outcome. Abciximab, however, did not improve outcome in the hospital (odds ratio [95% confidence interval]=0.96 [0.58 to 1.58]) or at 30 days (0.87 [0.53 to 1.41]), even after adjusting for these characteristics. Abciximab for stent placement was used in high-risk patients in our practice but was not associated with improved outcome.

Abciximab↗

PubMed1998

Reversible perfusion defects on exercise tomographic thallium imaging in patients with and without collateral flow.

A consecutive series of patients underwent exercise thallium imaging and coronary angiography that identified single-vessel right coronary artery disease. Redistribution in the left anterior descending territory was significantly associated with the presence of left-to-right collaterals, whereas collaterals were significantly less frequent in individuals who did not exhibit redistribution.

Adult↗

PubMed1998

Clinical outcomes after successful percutaneous coronary angioplasty of saphenous vein graft disease and the importance of long-term assessment.

We examined the short- and long-term outcome of 327 patients at Mayo Clinic who had undergone coronary angioplasty of saphenous vein graft stenoses to determine whether the traditional 6-month assessment of clinical end points after coronary angioplasty is as useful as it is for patients who have had angioplasty of native vessel disease. Follow-up over 3.3+/-2.7 years was performed. At 6 months, 96+/-1% of the patients were alive, whereas at the 1- and 5-year end points, survival had deteriorated to 92+/-2 and 67+/-3%, respectively. Only 80+/-2% were free of severe angina at 6 months and 62+/-3 and 36+/-3% after 1 and 5 years. Combined event-free rate for death, Q-wave myocardial infarction or repeat coronary artery bypass surgery was 86+/-2% at 6 months, 78+/-2% at 1 year, and 45+/-4% at 5 years. Independent predictors of mortality included advancing age, diabetes mellitus, target vein grafts >5 years old and left ventricular ejection fraction <40%. In conclusion, despite reasonable 6- to 12-month outcomes following vein graft angioplasty, significant attrition in survival and event-free survival was observed. These observations have important implications for the interpretation of results of trials comparing conventional angioplasty and coronary bypass surgery with newer interventional devices if only the traditional 6-month follow-up interval is used.

Aged↗

PubMed1998

Frequency of adverse clinical events in the 12 months following successful intracoronary stent placement in patients treated with aspirin and ticlopidine (without warfarin).

Little is known about the frequency of adverse events in the year following stent placement in patients treated with aspirin and ticlopidine, without warfarin. We analyzed the first such 234 consecutive patients treated at our hospital between October 1994 and December 1995. Their mean age was 62+/-12 years; 40% had had a prior myocardial infarction, 22% had undergone coronary artery bypass surgery, and 65% had multivessel disease. The indication for stent placement was dissection or abrupt closure in 24% of patients and suboptimal balloon angioplasty results in 14%; placement was elective in 62% of patients. Three hundred forty-five coronary segments were treated in the 234 patients; 305 stents (1.3 stents/patient) were placed. Palmaz-Schatz coronary stents (75%), Gianturco-Roubin stents (21%), and Johnson & Johnson biliary stents (4%) were used. Mean nominal stent size was 3.4+/-0.4 mm. High-pressure inflations (> or = 14 atm, mean 17+/-2) were performed in all patients. The mean residual stenosis was 3+/-5% by visual estimate. Intravascular ultrasound was utilized to facilitate stent placement in 53% of patients. Mean follow-up was 1.6+/-0.5 years. There were no deaths, Q-wave myocardial infarctions, coronary artery bypass operations, or repeat angioplasty procedures required during the remainder of the hospitalization or in 30 days after stent placement; stent thrombosis did not occur. Kaplan-Meier analysis of adverse events in the 6 months following the procedure revealed a mortality rate of 0.9%; the rate of myocardial infarction (Q-wave or non-Q-wave) was 1.3%. Bypass surgery was performed in 0.9% and angioplasty for in-stent restenosis was performed in 9.5% of patients. Any 1 of these events occurred in 11.7% of patients in the 6 months after the procedure. The corresponding event rates at 1 year were 1.3%, 2.2%, 3.5%, and 12.2%, respectively; any 1 of these events occurred in 16.5% of patients. In patients receiving intracoronary stents of varying designs followed by high-pressure postdeployment inflations in whom an excellent visual angiographic result is achieved, antithrombotic therapy with aspirin and ticlopidine is associated with a very low frequency of adverse cardiovascular events in the 12 months following the procedure regardless of the indication for stent placement.

Adult↗

PubMed1998

Clinical outcome of patients undergoing multivessel coronary stent implantation.

OBJECTIVES: To evaluate the outcome of patients undergoing multivessel coronary stent implantation. BACKGROUND: Percutaneous transluminal coronary angioplasty has been shown to be an effective treatment for multivessel coronary artery disease, although the need for repeat revascularization continues to be a limitation. Intracoronary stent placement has been shown to reduce the need for subsequent revascularization. METHODS: Seventy-seven patients without prior coronary artery bypass grafting (CABG) undergoing multivessel coronary revascularization in which stents were placed in all treated segments over a 5 year period at our institution were identified. Clinical and angiographic characteristics and outcomes were analyzed. RESULTS: One hundred and eighty-eight coronary lesions were successfully treated (2.1+/-0.3 treated vessels/patient, 2.4+/-0.6 treated lesions/patient) using 2.8+/-1.2 stents/patient (range 2-9) and 1.4+/-0.8 stents/vessel (range 1-6). Procedural success rate [angiographic success without in-hospital death, Q-wave myocardial infarction (Q-wave MI) or CABG] was achieved in 76 of 77 patients (98.7%). Anatomically complete revascularization was achieved in 46 (59.7%) patients. Modified ACC/AHA Type B2 and C lesions comprised 75.5% of the 188 lesions. The left anterior descending artery was treated in 57 (74.0%) patients. The indication for stent placement was dissection or threatened/abrupt closure in 54 segments (28.8%). In-hospital events included death in one patient (1.3%); no patient suffered a Q-wave MI or required CABG. Stent occlusion occurred in two (2.6%) patients, and repeat percutaneous intervention of the target vessel was also required in these two patients. Any of these adverse events occurred in three (3.9%) patients. No further events occurred after hospital discharge in the 30 days after the procedure. Of hospital survivors (n=76), adverse events at 6 months included death in two patients (2.6%), MI in two (2.6%), CABG in six (7.9%); nine (11.8%) patients underwent repeat percutaneous intervention and 15 (19.7%) underwent any revascularization. CONCLUSIONS: Multivessel coronary stent placement is associated with an excellent procedural success rate despite a high rate of adverse lesion characteristics, and a low rate of death or MI during follow-up. The need for further revascularization compares favorably with published rates with multivessel PTCA and single stent implantation for discrete de novo lesions.

Aged↗

PubMed1998

Cine film replacement: digital archival requirements and remaining obstacles.

The acceptance of the Digital Imaging and Communication in Medicine (DICOM) standard and the Compact Disk-Recordable (CD-R) as the interchange medium have been critical developments for laboratories that need to move forward on the cine replacement front, while at the same time retain a means to communicate with other centers. One remaining essential component which has not been satisfactorily addressed is the issue of how digital image data should be archived within an institution. Every laboratory must consider the diverse issues which affect the choice of a digital archiving system. These factors include technical and economic issues, along with the clinical routines prevailing in their laboratory. A complete understanding of the issues will lead to the formulation of multiple options which may prove acceptable and will help to overcome the last obstacle which remains for the complete replacement of cine film in the cardiac catheterization laboratory.

Archives↗

PubMed1998

Intravenous electron-beam computed tomographic coronary angiography for segmental analysis of coronary artery stenoses.

OBJECTIVES: We sought to identify and localize significant coronary stenoses on a segmental basis by electron-beam computed tomography (EBCT) and intravenous administration of a contrast agent. BACKGROUND: The clinical applicability and limitations of intravenous EBCT coronary angiography have not been defined. METHODS: EBCT was performed within 24 h of selective coronary angiography (SCA) in 28 patients (19 men and 9 women, mean [+/-SD] age 60 +/- 10 years). After examination for coronary calcium, EBCT coronary angiography was performed using overlapping slices (in-plane resolution 0.34 to 0.41 mm) with a nominal slice thickness of 1 mm. Based on quantitative analysis of SCA, lumen diameter narrowing > or = 50% (i.e., significant stenoses) was evaluated in 8 (major) or 12 (including side branches) coronary artery segments, using both two-dimensional (tomographic) and three-dimensional (volume) data sets. RESULTS: Of the 330 segments assessable by SCA, 237 (72%) were visualized by EBCT. The sensitivity (+/-SE) for detection of significant stenoses was 82 +/- 6%; specificity was 88 +/- 2%; positive and negative predictive values were 57 +/- 7% and 96 +/- 2%, respectively; and overall accuracy was 87 +/- 2%. If only eight (major) coronary artery segments were considered, 194 (88%) of 221 segments were visualized, and the overall accuracy was 90 +/- 2%. Seven (18%) of 38 significantly stenotic segments were classified as having < 50% stenoses by EBCT. Six of these segments (86%), but only 9 (29%) of the 31 correctly classified stenotic segments, were severely calcified (area > 20 mm2, p = 0.02). In 23 (12%) of 199 nonstenotic segments falsely classified as having > or = 50% stenosis by EBCT, the lumen diameter was significantly smaller than that of the segments correctly classified as negative (mean [+/-SD] 1.5 +/- 0.8 vs. 2.9 +/- 1.1 mm, p < 0.001). CONCLUSIONS: Intravenous EBCT coronary angiography allows for accurate segmental evaluation of significant disease in the major coronary arteries and may be of value for ruling out significant disease. The main determinant of false negative results is substantial segmental calcification, whereas the main determinant of false positive results is small vessel size.

Adult↗

PubMed1997

Outcome > or = 10 years after successful percutaneous transluminal coronary angioplasty.

Patients (n = 611) after successful percutaneous transluminal coronary angioplasty were prospectively followed over 10 to 16 years for major adverse events. The effect of gender, extent of coronary artery disease, left ventricular dysfunction, and age on occurrence of adverse events were analyzed in detail. The incidence of death, Q-wave myocardial infarction, and coronary bypass surgery was 23.1%, 3.9%, and 32.7%, respectively. Men and women had similar mortality (p = 0.13) and Q-wave myocardial infarction (p = 0.57), but men had more coronary bypass surgery (p = 0.06). Patients with multivessel disease had higher mortality (p < 0.0001), and patients with 3-vessel disease had a higher incidence of Q-wave myocardial infarction (p = 0.04) and coronary bypass surgery (p < 0.001). Left ventricular dysfunction was associated with higher mortality (p < 0.0001) and coronary bypass surgery (p = 0.045), but not Q-wave myocardial infarction (p = 0.99). Mortality was higher in elderly patients (p < 0.0001), but the incidence of Q-wave myocardial infarction was similar (p = 0.64). Older patients underwent coronary bypass surgery less often (p = 0.004). By multivariate analysis, only the extent of coronary disease (relative risk [RR] 1.71, confidence interval [CI] 1.34 to 2.19; p = 0.0001), diabetes mellitus (RR 1.82, CI 1.28 to 2.59; p = 0.001), hypertension (RR 1.30, CI 1.08 to 1.96, p = 0.009), male gender (RR 1.30, CI 0.99 to 1.71, p = 0.058), and prior myocardial infarction (RR 1.44, CI 1.14 to 1.81, p = 0.002) independently influenced the incidence of major adverse events. We conclude that it is possible to identify patients with worse long-term prognosis after percutaneous transluminal coronary angioplasty based on clinical and angiographic parameters.

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PubMed1997

The changing face of coronary interventional practice. The Mayo Clinic experience.

BACKGROUND: Devices designed to facilitate or replace conventional percutaneous transluminal coronary angioplasty have been introduced in recent years. OBJECTIVES: To characterize the changes in percutaneous coronary interventional practice over 16 years and to assess the relative use of these new devices. METHODS: We performed a retrospective analysis of all patients who underwent percutaneous coronary revascularization at Mayo Clinic, Rochester, Minn, during a 16-year period (1980-1995) and characterized the changes in procedural and clinical factors. RESULTS: The number of coronary interventional procedures performed increased from 38 in 1980 to 1284 in 1995. Atherectomy and laser angioplasty were incorporated in 1988; their use peaked in 1994 (17% of procedures) but decreased to 9.9% by 1995. In contrast, the use of intracoronary stents has increased steadily since 1990. By 1995, intracoronary stents were placed in 48.2% of procedures. The success rate improved from 55.3% in 1980 to 91.4% in 1995, although patients were older (51 +/- 10 [mean +/- SD] years in 1980 vs 63 +/- 12 years in 1995), had more extensive coronary artery disease (0% with multivessel disease in 1980 vs 47.4% in 1995), had more complex lesions, and often underwent intervention in the peri-infarction setting (2.6% of procedures in 1980 vs 17% in 1995). The rate of referral to emergency coronary bypass surgery after percutaneous procedures declined from 5.2% in 1980 to 0.4% in 1995. CONCLUSIONS: Current coronary interventional practice is expanding and improving. In contrast to intracoronary stents that have greatly affected current practice, other new devices are used infrequently. Conventional angioplasty, with or without intracoronary stents, remains the dominant treatment strategy.

Adult↗

PubMed1997

Sex and test verification bias. Impact on the diagnostic value of exercise echocardiography.

BACKGROUND: The use of exercise echocardiography for the diagnosis of coronary artery disease (CAD) has been validated in pilot studies but is not documented in clinical practice and in women comparatively with men. The objectives of this study were to determine the effects of sex and of test verification bias on the diagnostic performance of exercise echocardiography. METHODS AND RESULTS: Three thousand six hundred seventy-nine consecutive patients (1714 women, 1965 men) who underwent an exercise echocardiographic study were studied; the observed sensitivity, specificity, and correct classification rate were calculated among 340 patients (244 men, 96 women) who underwent angiography; to study the effect of test verification bias, sensitivity and specificity were estimated for all patients who underwent exercise echocardiography including those not referred to angiography. In the angiographic group, the prevalence of CAD was 60% in women and 80% in men. The observed sensitivity and specificity of exercise echocardiography was 78% and 44% in men and 79% and 37% in women. After adjustment for test verification bias, the estimated sensitivity was lower in women (32% versus 42% in men), whereas specificity was similar in both sexes. The positive predictive value was lower in women (66%) compared with men (84%). CONCLUSIONS: In clinical practice, test verification bias results in a lower observed specificity and a higher sensitivity of exercise echocardiography. In women, positive predictive value and adjusted sensitivity are lower compared with that in men.

Aged↗