Ryan J. Lennon

The impact of renal insufficiency on clinical outcomes in patients undergoing percutaneous coronary interventions

OBJECTIVES We sought to determine the effect of varying degrees of renal insufficiency on death and cardiac events during and after a percutaneous coronary intervention (PCI). BACKGROUND Patients with end-stage renal disease have a high mortality from coronary artery disease. Little is known about the impact of mild and moderate renal insufficiency on clinical outcomes after PCI. METHODS Cardiac mortality and all-cause mortality were determined for 5,327 patients undergoing PCI from January 1, 1994, to August 31, 1999, at the Mayo Clinic, based on the estimated creatinine clearance or whether the patient was on dialysis. RESULTS In-hospital mortality was significantly associated with renal insufficiency (p = 0.001). Even after successful PCI, one-year mortality was 1.5% when the creatinine clearance was > or =70 ml/min (n = 2,558), 3.6% when it was 50 to 69 ml/min (n = 1,458), 7.8% when it was 30 to 49 ml/min (n = 828) and 18.3% when it was < 30 ml/min (n = 141). The 18.3% mortality rate for the group with < 30 ml/min creatinine clearance was similar to the 19.9% mortality rate in patients on dialysis (n = 46). The mortality risk was largely independent of all other factors. CONCLUSIONS Renal insufficiency is a strong predictor of death and subsequent cardiac events in a dose-dependent fashion during and after PCI. Patients with renal insufficiency have more baseline cardiovascular risk factors, but renal insufficiency is associated with an increased risk of death and other adverse cardiovascular events, independent of all other measured variables.

Clinical outcome of patients undergoing non-cardiac surgery in the two months following coronary stenting

OBJECTIVES We sought to determine the frequency and timing of complications at our institution when surgery was performed within two months of coronary stent placement. BACKGROUND The optimal delay following coronary stent placement prior to non-cardiac surgery is unknown. METHODS We analyzed the Mayo Clinic Percutaneous Coronary Intervention and Surgical databases between 1990 and 2000 and identified 207 patients who underwent surgery in the two months following successful coronary stent placement. RESULTS Eight patients (4.0%) died or suffered a myocardial infarction or stent thrombosis. All 8 patients were among the 168 patients (4.8%, 95% confidence interval [CI] 2.1 to 9.2) undergoing surgery six weeks after stent placement; the frequency of these events ranged from 3.8% to 7.1% per week during each of the six weeks. No events occurred in the 39 patients undergoing surgery seven to nine weeks after stent placement (0%, 95% CI 0.0 to 9.0). CONCLUSIONS These data suggest that, whenever possible, non-cardiac surgery should be delayed six weeks after stent placement, by which time stents are generally endothelialized, and a course of antiplatelet therapy to prevent stent thrombosis has been completed.

Assessment of endothelial function by non-invasive peripheral arterial tonometry predicts late cardiovascular adverse events

AIMS There is growing need for the identification of novel non-invasive methodologies for the identification of individuals at risk for adverse cardiovascular (CV) events. We examined whether endothelial dysfunction, as detected by non-invasive peripheral arterial tonometry (EndoPAT), can predict late CV events. METHODS AND RESULTS Reactive hyperaemia (RH) was induced following upper arm occlusion of systolic blood pressure in 270 outpatients (54 +/- 12 years, 48% female). The natural logarithmic scaled RH index (L_RHI) was calculated from the ratio between the digital pulse volume during RH and at baseline. The patients were followed for CV adverse events (AE: cardiac death, myocardial infarction, revascularization or cardiac hospitalization) during a 7-year follow-up (inter-quartile range = 4.4-8). Cox models were used to estimate the association of EndoPAT results with AE adjusted for age. During the follow-up, AE occurred in 86 patients (31%). Seven-year AE rate was 48% in patients with L_RHI < 0.4 vs. 28% in those with L_RHI >or= 0.4 (P = 0.03). Additional univariate predictors of AE were advancing age (P = 0.02) and prior coronary bypass surgery (P = 0.01). The traditional Framingham risk score was not higher in patients with AE. Multivariate analysis identified L_RHI < 0.4 as an independent predictor of AE (P = 0.03). CONCLUSION A low RH signal detected by EndoPAT, consistent with endothelial dysfunction, was associated with higher AE rate during follow-up. L_RHI was an independent predictor of AE. Non-invasive assessment of peripheral vascular function may be useful for the identification of patients at risk for cardiac AEs.

Clinical Features, Management, and Prognosis of Spontaneous Coronary Artery Dissection

Background— Spontaneous coronary artery dissection (SCAD) is an acute coronary event of uncertain origin. Clinical features and prognosis remain insufficiently characterized. Methods and Results— A retrospective single-center cohort study identified 87 patients with angiographically confirmed SCAD. Incidence, clinical characteristics, treatment modalities, in-hospital outcomes, and long-term risk of SCAD recurrence or major adverse cardiac events were evaluated. Mean age was 42.6 years; 82% were female. Extreme exertion at SCAD onset was more frequent in men (7 of 16 versus 2 of 71; P<0.001), and postpartum status was observed in 13 of 71 women (18%). Presentation was ST-elevation myocardial infarction in 49%. Multivessel SCAD was found in 23%. Initial conservative management (31 of 87) and coronary artery bypass grafting (7 of 87) were associated with an uncomplicated in-hospital course, whereas percutaneous coronary intervention was complicated by technical failure in 15 of 43 patients (35%) and 1 death. During a median follow-up of 47 months (interquartile range, 18–106 months), SCAD recurred in 15 patients, all female. Estimated 10-year rate of major adverse cardiac events (death, heart failure, myocardial infarction, and SCAD recurrence) was 47%. Fibromuscular dysplasia of the iliac artery was identified incidentally in 8 of 16 femoral angiograms (50%) undertaken before closure device placement and in the carotid arteries of 2 others with carotid dissection. Conclusions— SCAD affects a young, predominantly female population, frequently presenting as ST-elevation myocardial infarction. Although in-hospital mortality is low regardless of initial treatment, percutaneous coronary intervention is associated with high rates of complication. Risks of SCAD recurrence and major adverse cardiac events in the long term emphasize the need for close follow-up. Fibromuscular dysplasia is a novel association and potentially causative factor.

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.

Trends in Outcomes After Percutaneous Coronary Intervention for Chronic Total Occlusions: A 25-Year Experience From the Mayo Clinic

OBJECTIVES The aim of our study was to examine the trends in procedural success, in-hospital, and long-term outcomes after percutaneous coronary intervention (PCI) for chronic total occlusions (CTO) over the last 25 years from a single PCI registry and to examine the impact of drug-eluting stents. BACKGROUND The percutaneous treatment of CTO remains a major challenge. Past studies have used variable definitions of CTO, and there are limited data available from contemporary practice. METHODS We evaluated the outcomes of 1,262 patients from the Mayo Clinic registry who required PCI for a CTO. The patients were divided into 4 groups according to the time of their intervention: group 1 (percutaneous transluminal coronary angioplasty era), group 2 (early stent era), group 3 (bare-metal stent era), and group 4 (drug-eluting stent era). RESULTS Procedural success rates were 51%, 72%, 73%, and 70% (p < 0.001), respectively, in the 4 groups. In-hospital mortality (2%, 1%, 0.4%, and 0%, p = 0.009), emergency coronary artery bypass grafting (15%, 3%, 2%, and 0.7%, p < 0.001), and rates of major adverse cardiac events (8%, 5%, 3%, and 4%, p = 0.052) decreased over time. During follow-up, the combined end point of death, myocardial infarction, or target lesion revascularization, was significantly lower in the 2 most recent cohorts compared with those patients treated before (p = 0.001 for trend). Technical failure to treat the CTO was not an independent predictor of long-term mortality (hazard ratio 1.16 [95% confidence interval 0.90 to 1.5], p = 0.25). CONCLUSIONS Procedural success rates for CTO have not improved over time in the stent era, highlighting the need to develop new techniques and devices. Compared with the prestent era, in-hospital major adverse cardiac events and 1-year target vessel revascularization rates have declined by approximately 50%.

Impact of Cardiac Rehabilitation on Mortality and Cardiovascular Events After Percutaneous Coronary Intervention in the Community

Background— Although numerous studies have reported that cardiac rehabilitation (CR) is associated with reduced mortality after myocardial infarction, less is known about its association with mortality after percutaneous coronary intervention. Methods and Results— We performed a retrospective analysis of data from a prospectively collected registry of 2395 consecutive patients who underwent percutaneous coronary intervention in Olmsted County, Minnesota, from 1994 to 2008. The association of CR with all-cause mortality, cardiac mortality, myocardial infarction, or revascularization was assessed with 3 statistical techniques: propensity score–matched analysis (n=1438), propensity score stratification (n=2351), and regression adjustment with propensity score in a 3-month landmark analysis (n=2009). During a median follow-up of 6.3 years, 503 deaths (199 cardiac), 394 myocardial infarctions, and 755 revascularization procedures occurred in the study subjects. Participation in CR, noted in 40% (964 of 2395) of the cohort, was associated with a significant decrease in all-cause mortality by all 3 statistical techniques (hazard ratio, 0.53 to 0.55; P<0.001). A trend toward decreased cardiac mortality was also observed in CR participants; however, no effect was observed for subsequent myocardial infarction or revascularization. The association between CR participation and reduced mortality rates was similar for men and women, for older and younger patients, and for patients undergoing elective or nonelective percutaneous coronary intervention. Conclusions— We found that CR participation after percutaneous coronary intervention was associated with a significant reduction in mortality rates. These findings add support to published clinical practice guidelines, performance measures, and insurance coverage policies that recommend CR for patients after percutaneous coronary intervention.

Obesity is independently associated with coronary endothelial dysfunction in patients with normal or mildly diseased coronary arteries

OBJECTIVES This study evaluates the impact of obesity on coronary endothelial function in patients with normal or mild coronary artery disease. BACKGROUND The American Heart Association (AHA) has recently classified obesity as a modifiable risk factor for coronary heart disease. METHODS A total of 397 consecutive patients with normal or mildly diseased coronary arteries at angiography underwent coronary vascular reactivity evaluation using intracoronary adenosine, acetylcholine and nitroglycerin. Patients were divided into three groups based on the body mass index (BMI): Group 1, patients with a BMI <25 (n = 117, normal weight); Group 2, patients with a BMI 25-30 (n = 149, overweight) and Group 3, patients with a BMI >30 (n = 131, obese). RESULTS There were no significant differences among the groups in regard to other cardiovascular risk factors, except that overweight but not obese patients were significantly older than normal-weight patients (47 +/- 1 years in Group 1, 53 +/- 1 years in Group 2 and 50 +/- 1 years in Group 3, p < 0.001). The percent change of coronary blood flow to acetylcholine (%delta CBF Ach) was significantly lower in the obese patients than in the normal-weight group (85.2 +/- 12.0% in Group 1, 63.7 +/- 10.0% in Group 2 and 38.1 +/- 9.6% in Group 3, p = 0.009). By multivariate analysis, overweight (odds ratio, 1.55; 95% confidence interval, 1.2-2.0) and obesity (odds ratio, 2.41; 95% confidence interval, 1.5-4.0) status were independently associated with impaired coronary endothelial function. CONCLUSIONS The study demonstrates that obesity is independently associated with coronary endothelial dysfunction in patients with normal or mildly diseased coronary arteries.

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.

Major Femoral Bleeding Complications After Percutaneous Coronary Intervention: Incidence, Predictors, and Impact on Long-Term Survival Among 17,901 Patients Treated at the Mayo Clinic From 1994 to 2005

OBJECTIVES The purpose of this study was to evaluate secular trends and factors associated with major femoral bleeding after percutaneous coronary intervention (PCI) in routine clinical practice during the past decade and to assess the impact of these complications on outcomes including mortality. BACKGROUND Significant changes in patient demographic data, adjunctive pharmacotherapy, and access site management have occurred during the coronary stent era. Trends in major vascular complications after PCI during this time have not been well characterized. METHODS Consecutive patients who underwent transfemoral PCI from 1994 to 2005 at the Mayo Clinic (n = 17,901) were studied. Patients were divided into 3 groups: Group 1 (1994 to 1995, n = 2,441); Group 2 (1996 to 1999, n = 6,207); and Group 3 (2000 to 2005, n = 9,253). RESULTS The incidence of major femoral bleeding complications decreased (from 8.4% to 5.3% to 3.5%; p < 0.001). Reductions in sheath size, intensity and duration of anticoagulation with heparin, and procedure time were observed (p < 0.001), and multivariate analysis confirmed each as an independent predictor of complications (p < 0.001). Adverse outcomes of major femoral bleeding included prolonged hospital stay (mean 4.5 vs. 2.7 days; p < 0.0001) and increased requirement for blood transfusion (39% vs. 4.7%; p < 0.0001). Major femoral bleeding and blood transfusion were both associated with decreased long-term survival, driven by a significant increase in 30-day mortality (p < 0.001 for both). CONCLUSIONS We noted a marked decline in the incidence of major femoral bleeding after PCI over the past decade. Mortality associated with these bleeding complications and with blood transfusion remains a significant issue.