John F. Bresnahan

Continuous-wave Doppler echocardiographic assessment of severity of calcific aortic stenosis: a simultaneous Doppler-catheter correlative study in 100 adult patients.

Studies of the correlation of aortic valve gradient determined by continuous-wave Doppler echocardiography and that determined at catheterization have, to date, involved young patients and nonsimultaneous measurements. We therefore obtained simultaneous Doppler echocardiographic and catheter measurements of pressure gradient in 100 consecutive adults (mean age 69, range 50 to 89 years). In 63 patients pressure measurements were obtained with dual-catheter techniques and in 37 they were obtained by withdrawal of the catheter from the left ventricle to the ascending aorta. Forty-six of these patients also underwent an outpatient Doppler study 7 days or less before catheterization. The simultaneous pressure waveforms and Doppler spectral velocity profiles were digitized at 10 msec intervals and maximum, mean, and instantaneous gradients (mm Hg) were derived for each. The correlation between the Doppler-determined gradient and the simultaneously measured maximum catheter gradient was r = .92 (SEE = 15 mm Hg), that between the Doppler-determined and mean catheter gradient was r = .93 (SEE = 10 mm Hg), and that between the Doppler and peak-to-peak catheter gradient was r = .91 (SEE = 14). The correlation between the nonsimultaneously Doppler-determined gradient and the maximum gradient measured by catheter was not as strong (r = .79, SEE = 24). The continuous-wave Doppler echocardiographic velocity profile represents the instantaneous transaortic pressure gradient throughout the cardiac cycle. The best correlation with continuous-wave Doppler-determined gradient was obtained with maximum and mean gradients measured by catheter. Continuous-wave Doppler echocardiography can be used to reliably predict the pressure gradient in adults with calcific aortic stenosis.

Regional Systems of Care to Optimize Timeliness of Reperfusion Therapy for ST-Elevation Myocardial Infarction The Mayo Clinic STEMI Protocol

Background— Quality improvement efforts have focused on strategies to improve the timeliness of reperfusion therapy in ST-elevation myocardial infarction patients who present to hospitals with and without percutaneous coronary intervention (PCI) capability. We implemented and evaluated a protocol to optimize the timeliness of reperfusion therapy and to coordinate systems of care for a PCI center and 28 regional hospitals located up to 150 miles away across 3 states. Methods and Results— The present study focused on a prospective, observational cohort of 597 patients who presented with ST-segment elevation and within 12 hours of symptom onset to Saint Marys Hospital and 28 regional hospitals up to 150 miles away between May 2004 and December 2006. The Mayo Clinic ST-elevation myocardial infarction protocol implemented strategies to improve timeliness of reperfusion therapy and to coordinate systems of care for transfer between hospitals. The study sample consisted of 258 patients who presented to Saint Marys Hospital and were treated with primary PCI (group A), 105 patients who presented to a regional hospital with symptom onset >3 hours and then were transferred for primary PCI (group B), and 131 patients who presented to a regional hospital with symptom onset <3 hours and were treated with full-dose fibrinolytic therapy (group C). For groups A and B, median door-to-balloon times were 71 and 116 minutes, respectively. Door-to-balloon time <90 minutes was achieved in 75% of group A and 12% of group B. Median door-to-needle time was 25 minutes for group C, and 70% had door-to-needle time <30 minutes. Conclusions— The Mayo Clinic ST-elevation myocardial infarction protocol demonstrates the feasibility of implementing strategies to optimize the timeliness of reperfusion therapy and the times that can be achieved through coordinated systems of care for ST-elevation myocardial infarction patients presenting to a PCI center (Saint Marys Hospital) and 28 regional hospitals without PCI capability located up to 150 miles away across 3 states.

Intracoronary thrombus: Role in coronary occlusion complicating percutaneous transluminal coronary angioplasty

Angiograms from 238 consecutive patients who underwent percutaneous transluminal coronary angioplasty at the Mayo Clinic were reviewed to determine the presence of intracoronary thrombus before dilation. Patients with previously occluded vessels and those receiving streptokinase therapy were excluded. Intracoronary thrombus before dilation was present in 15 patients (6%); complete occlusion occurred in 11 (73%) of these during or immediately after dilation. None of these patients had angiographic evidence of major intimal dissection. In contrast, among the 223 patients in whom no intracoronary thrombus was present before dilation, complete occlusion occurred in 18 (8%) and in 12 was associated with major intimal dissection. The difference between the complete occlusion rates for patients with and without prior intracoronary thrombus was highly significant (73 versus 8%, respectively, p less than 0.001). Therefore, the presence of intracoronary thrombus identifies a group of patients who are at increased risk of developing complete occlusion during or after attempted coronary artery dilation.

Immediate and long-term outcome of intracoronary stent implantation for true bifurcation lesions

OBJECTIVES The aim of this study was to evaluate the immediate and long-term outcome of intracoronary stent implantation for the treatment of coronary artery bifurcation lesions. BACKGROUND Balloon angioplasty of true coronary bifurcation lesions is associated with a lower success and higher complication rate than most other lesion types. METHODS We treated 131 patients with bifurcation lesions with > or =1 stent. Patients were divided into two groups; Group (Gp) 1 included 77 patients treated with a stent in one branch and percutaneous transluminal coronary angioplasty (PTCA) (with or without atherectomy) in the side branch, and Gp 2 included 54 patients who underwent stent deployment in both branches. The Gp 2 patients were subsequently divided into two subgroups depending on the technique of stent deployment. The Gp 2a included 19 patients who underwent Y-stenting, and Gp 2b included 33 patients who underwent T-stenting. RESULTS There were no significant differences between the groups in terms of age, gender, frequency of prior myocardial infarction (MI) or coronary artery bypass grafting (CABG), or vessels treated. Procedural success rates were excellent (89.5 to 97.4%). After one-year follow-up, no significant differences were seen in the frequency of major adverse events (death, MI, or repeat revascularization) between Gp 1 and Gp 2. Adverse cardiac events were higher with Y-stenting compared with T-stenting (86.3% vs. 30.4%, p = 0.004). CONCLUSIONS Stenting of bifurcation lesions can be achieved with a high success rate. However, stenting of both branches offers no advantage over stenting one branch and performing balloon angioplasty of the other branch.

Outcomes of Stent Thrombosis and Restenosis During Extended Follow-Up of Patients Treated With Bare-Metal Coronary Stents

Background— Concern regarding risk of late thrombosis after “off-label” treatment with drug-eluting stents has prompted increased use of bare-metal stents (BMS) in current practice. The sequelae of late BMS failures, however, have been poorly characterized. Methods and Results— We performed a retrospective study of 4503 consecutive patients treated with at least 1 BMS and dual antiplatelet therapy between 1994 and 2000. The cumulative incidence of stent thrombosis was 0.5% at 30 days (95% CI, 0.3% to 0.7%), 0.8% at 1 year (95% CI, 0.6% to 1.1%), and 2.0% at 10 years (95% CI, 1.5% to 2.5%). Risk of late (30 days to 1 year) and very late (>1 year) BMS thrombosis was increased among patients considered off label for drug-eluting stent use (P=0.024). When saphenous vein graft interventions were excluded, however, risk after off-label use was not significantly increased (P=0.23). Other correlates included vein graft intervention, prior myocardial infarction (MI), peripheral vascular disease, and ulcerated lesion (P<0.001). Mortality was markedly increased after late and very late BMS thrombosis, particularly during the first 30 days (hazard ratios, 22 [95% CI, 3.1 to 159] and 40 [95% CI, 15 to 107], respectively). The 10-year incidence of clinical restenosis was 18.1% (95% CI, 16.5% to 19.7%), presenting with MI in 2.1% (95% CI, 1.6% to 2.6%). Restenosis presenting with MI was associated with increased mortality compared with no restenosis (hazard ratio, 2.37; P<0.001) and with restenosis with a non-MI presentation (hazard ratio, 2.42; P<0.001). Conclusions— The incidence of BMS thrombosis and of MI caused by restenosis during extended follow-up is significant. Both complications are associated with mortality.

Initial and long-term outcome of 354 patients after coronary balloon angioplasty of total coronary artery occlusions.

BackgroundCoronary balloon angioplasty of chronic total occlusions is associated with relatively low success rates and a high incidence of restenosis. Whether there is long-term benefit in performing angioplasty of these lesions is unknown. The purpose of the present report was to analyze the long-term outcome of a large series of patients undergoing this procedure. Methods and ResultsA computerized database analysis of 354 consecutive patients (from 1979 to 1990) who underwent coronary angioplasty of a chronic total coronary occlusion was performed (mean age, 62.3 years). Initial technical success was achieved in 69%; in 66%, success was achieved without procedural death or need for coronary artery surgery. During hospitalization, six patients suffered myocardial infarction, nine required emergency bypass surgery, and nine patients died. During a mean follow-up period of 2.7 years, no difference was found in survival or freedom from myocardial infarction among 234 successfully dilated patients compared with 120 patients with a failed attempt. However, the use of coronary artery bypass surgery was significantly less after successful dilation (p<0.0001 versus failed attempt). No significant difference in the cumulative incidence of severe angina was observed between these two patient populations, with the majority remaining asymptomatic. Restenosis occurred in 59% of 69 patients who returned for follow-up angiography. ConclusionsSuccessful recanalization is achieved in the majority of patients undergoing angioplasty of chronic total occlusions and reduces the need for coronary artery bypass surgery. However, no major impact on either survival or incidence of myocardial infarction was noted after successful recanalization when patients with surgery were included.

Follow-up clinical results in patients undergoing percutaneous transluminal coronary angioplasty.

Complete follow-up data were obtained from 229 consecutive patients who underwent percutaneous transluminal coronary angioplasty (PTCA) between 1979 and 1982 (mean follow-up 14 months, range 6 to 37). Single-vessel disease was present in 143 and multivessel disease in 86. PTCA was successful in 153 patients (67%). Failure was followed initially by bypass surgery in 59 and by continued medical therapy in 17. After successful PTCA, 90% of patients were improved subjectively and 74% were asymptomatic at follow-up. After unsuccessful PTCA but prompt bypass, 90% were improved subjectively and 85% were asymptomatic. Among the 229 patients, 39 (17%) required an additional intervention because of angina during follow-up; 15 of these had repeat PTCA and 18 had bypass surgery. Among patients with successful PTCA, revascularization was complete in 77% and partial in 23%. The completeness of revascularization with PTCA had a significant impact on follow-up. The follow-up data of patients with successful single-vessel PTCA and of those with multivessel disease with complete revascularization were similar. When the patients with complete revascularization were compared with those with multivessel disease but incomplete revascularization, the follow-up data were characterized by a higher incidence of angina or need for bypass surgery in the latter group (63%) than in the former group (29%); those with incomplete revascularization also had a significantly reduced event-free survival.

Outcome of Noncardiac Operations in Patients With Severe Coronary Artery Disease Successfully Treated Preoperatively With Coronary Angioplasty

The risk of perioperative myocardial infarction and death was evaluated in 50 patients (mean age, 68 years) with severe coronary artery disease who underwent a noncardiac operation after revascularization had been achieved by successful percutaneous transluminal coronary angioplasty. Before angioplasty, all patients were thought to be at high risk for perioperative complications on the basis of assessment of clinical variables and findings on specialized diagnostic tests. Of the 50 patients, 31 had Canadian Heart Association class III or IV angina or unstable angina. All patients who underwent functional testing had positive results. At catheterization, 38 patients (76%) had multivessel disease. The 50 patients underwent 54 noncardiac operations at a median of 9 days after angioplasty. The overall frequency of perioperative myocardial infarction was 5.6%, and the mortality was 1.9%. Two nonfatal non-Q-wave infarctions and one fatal Q-wave infarction occurred. In patients who have undergone successful angioplasty for severe coronary artery disease, the risk of major cardiac complications associated with a noncardiac surgical procedure is low.

Percutaneous transluminal coronary angioplasty in patients with cardiogenic shock

In cardiogenic shock complicating acute myocardial infarction, percutaneous transluminal coronary angioplasty has been reported to significantly improve the modest survival benefits afforded by emergency surgical revascularization and thrombolytic therapy. The records of all patients who underwent angioplasty for acute myocardial infarction complicated by cardiogenic shock were retrospectively reviewed to determine whether coronary angioplasty improves survival. Of the 45 patients, 28 (group 1, 62%) had successful dilation of the infarct-related artery and 17 (group 2, 38%) had unsuccessful angioplasty. The groups were similar in extent of coronary artery disease, infarct location, incidence of multivessel disease and hemodynamic variables. The overall hospital survival rate was 56% (71% in group 1 and 29% in group 2). Group 1 patients had more left main coronary artery disease, and group 2 patients were older and had a higher incidence of prior myocardial infarction. Multivariate analysis showed that the survival advantage in patients with successful angioplasty was statistically significant (p = 0.014) when these factors were taken into account. At a mean follow-up interval of 2.3 years (range 1 month to 5.6 years), there were five deaths (four cardiac and one noncardiac), for a 2.3-year survival rate of 80% in patients surviving to hospital discharge. During the follow-up period, 36% of hospital survivors had repeat hospitalization for cardiac evaluation, 8% had myocardial infarction, 8% had coronary artery bypass surgery and 24% had angina.

Percutaneous excimer laser coronary angioplasty: Results in the first consecutive 3,000 patients

OBJECTIVES We report the comprehensive results of the first consecutive 3,000 patients treated in an excimer laser coronary angioplasty registry. BACKGROUND Excimer laser coronary angioplasty involves the use of a pulsed, 308-nm ultraviolet laser transmitted by optical fibers to reduce coronary stenoses. Preliminary reports have described safety and efficacy profiles in small numbers of patients. METHODS Patients were enrolled in a prospective, nonrandomized manner. The catheters used were 1.3, 1.6, 2.0, 2.2 and 2.4 mm in diameter, at energy densities up to 70 mJ/mm2. Procedures were performed by standard angioplasty technique with conventional guide catheters. RESULTS Seventy-five percent of patients were male, 68% were in Canadian Cardiovascular Society functional class III or IV and the cohort included 3,592 lesions. Procedural success (final stenosis < or = 50% without in-hospital Q wave myocardial infarction, coronary artery bypass surgery or death) was 90% and did not differ between the first 2,000 and the last 1,000 patients treated. There was no significant difference in success or complication rates with respect to lesion length, nor were there differences between selected complex and simple lesions. Complications included in-hospital bypass surgery (3.8%), Q wave myocardial infarction (2.1%) and death (0.5%). Coronary artery perforation occurred in 1.2% of patients (1% of lesions) but significantly decreased to 0.4% in the last 1,000 patients (0.3% of lesions). Angiographic dissection occurred in 13% of lesions, transient occlusion in 3.4% and sustained occlusion in 3.1%. Comprehensive lesion morphologic data collected in the latter portion of the study showed the procedure predominantly limited to American College of Cardiology-American Heart Association type B2 and C lesions, with no significant difference in short-term outcome between groups. CONCLUSIONS Excimer laser angioplasty can be safely and effectively applied, even in a variety of complex lesions not well suited for percutaneous transluminal coronary angioplasty. These types may include aorto-ostial, long lesions, total occlusions crossable with a wire, diffuse disease and vein grafts. Most recent data show a trend for the selection of predominantly complex lesions and a reduction in the incidence of perforation. This procedure may broaden the therapeutic window for the interventional treatment of selected complex coronary artery disease.Objectives. We report the comprehensive results of the first consecutive 3,000 patients treated in an excimer laser coronary angioplasty registry. Background. Excimer laser coronary angioplasty involves the use of a pulsed, 308-nm ultraviolet laser transmitted by optical fibers to reduce coronary stenoses. Preliminary reports have described safety and efficacy profiles in small numbers of patients. Methods. Patients were enrolled in a prospective, nonrandomized manner. The catheters used were 1.3, 1.6, 2.0, 2.2 and 2.4 mm in diameter, at energy densities up to 70 mJ/mm2. Procedures were performed by standard angioplasty technique with conventional guide catheters. Results. Seventy-five percent of patients were male, 68% were in Canadian Cardiovascular Society functional class III or IV and the cohort included 3,592 lesions. Procedural success (final stenosis ≤50% without in-hospital Q wave myocardial infarction, coronary artery bypass surgery or death) was 90% and did not differ between the first 2,000 and the last 1,000 patients treated. There was no significant difference in success or complication rates with respect to lesion length, nor were there differences between selected complex and simple lesions. Complications included in-hospital bypass surgery (3.8%), Q wave myocardial infarction (2.1%) and death (0.5%). Coronary artery perforation occurred in 1.2% of patients (1% of lesions) but significantly decreased to 0.4% in the last 1,000 patients (0.3% of lesions). Angiographic dissection occurred in 13% of lesions, transient occlusion in 3.4% and sustained occlusion in 3.1%. Comprehensive lesion morphologic data collected in the latter portion of the study showed the procedure predominantly limited to American College of Cardiology-American Heart Association type B2 and C lesions, with no significant difference in short-term outcome between groups. Conclusions. Excimer laser angioplasty can be safely and effectively applied, even in a variety of complex lesions not well suited for percutaneous transluminal coronary angioplasty. These types may include aorto-ostial, long lesions, total occlusions crossable with a wire, diffuse disease and vein grafts. Most recent data show a trend for the selection of predominantly complex lesions and a reduction in the incidence of perforation. This procedure may broaden the therapeutic window for the interventional treatment of selected complex coronary artery disease.