Lennon, Ryan J.

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.

Aims: Percutaneous coronary intervention (PCI) is frequently accompanied by myocardial injury. The present study was performed to determine whether remote ischemic preconditioning (IP) induces cardioprotection during PCI. Methods: We enrolled 95 patients requiring nonemergency PCI for stable disease or unstable angina into this prospective clinical trial. Patients were randomized to either remote IP (induced by three 3‐min cycles of blood pressure cuff inflations to 200 mm Hg around the upper arm, followed by 3‐min of reperfusion n = 47) or sham control ( n = 48) immediately preceding PCI. The primary outcome measure was the frequency of post‐PCI myonecrosis, defined as a peak postprocedural cTnT T ≥0.03 ng/dL. Secondary outcome measures were the change in plasma high‐sensitivity C‐reactive protein (hsCRP) levels following PCI and in endothelial progenitor cells (EPC) counts following IP. Results: There was no difference in the primary endpoint of the frequency of PCI related myonecrosis which occurred in 22 (47%) and 19 (40%) patients in the remote IP and control groups, respectively, P = 0.42. There was significant increase in hsCRP post‐PCI in both groups ( P < 0.001), but there was no difference between the groups (median %change in hsCRP 46% vs. 54%, P = 0.73). There was no significant change in circulating early (CD34 −/CD133+/KDR+), intermediate (CD34+/CD133+/KDR+), or late (CD34+/CD133−/KDR+) EPC in the two groups immediately following IP. The composite rate of death, myocardial infarction, and target lesion revascularization at 1 year was 14.1% versus 13.7% ( P = 0.90). Conclusions: Our study indicates that remote IP immediately before PCI does not induce cardioprotection in low to moderate risk patients. © 2012 Wiley Periodicals, Inc.

Background— Clinical outcomes after stent placement in patients with a history of metal allergy remain incompletely understood. We performed a single-center retrospective study to evaluate such outcomes. Methods and Results— Twenty-nine allergic patients who underwent coronary stent implantation were compared with a nonallergic group (n=250) matched for demographics and a propensity score for allergy to metal. Hypersensitivity to nickel was reported in 26 of 29 and chromium in 9 of 29. Patch testing performed in 11 of 29 patients was positive in all. Comparing allergy versus control subjects, there were no differences in number of segments treated (1.4±0.7 versus 1.5±0.7), stents placed (1.7±1.1 versus 1.6±0.9), and frequency of drug-eluting stent usage (52% versus 60%). In-hospital death (0% versus 0%), myocardial infarction (MI, 4% versus 3%, P =0.27), and 30-day death (3% versus 0%, P =0.53) and MI (3% versus 4%, P =0.71) were statistically similar. There were no differences in 4-year death (12% versus 13%), target lesion revascularization (TLR, 13 versus 17%, P =0.54), or death/MI/TLR (24% versus 34%, P =0.20). Clinically driven repeat angiography in 12 of 29 allergy patients revealed binary restenosis rates of 27% in bare metal stents and 0% in drug-eluting stents, with mean diameter in-stent restenosis of 36% and 8%, respectively. There was no change in circulating eosinophil and lymphocyte counts after stenting in the allergy group (0.19–0.20, P =0.67, and 1.90–1.79, P =0.59, respectively). Conclusions— A history of metal allergy was not associated with adverse early or late outcomes in this single-center study.

Background— Although older patients frequently undergo percutaneous coronary interventions (PCI), frailty, comorbidity, and quality of life are seldom part of risk prediction approaches. We assessed their incremental prognostic value over and above the risk factors in the Mayo Clinic risk score. Methods and Results— Patients ≥65 years who underwent PCI were assessed for frailty (Fried criteria), comorbidity (Charlson index), and quality of life [SF-36]. Of the 628 discharged [median follow-up of 35.0 months (interquartile range, 22.7 to 42.9)], 78 died and 72 had a myocardial infarction (MI). Three-year mortality was 28% for frail patients, 6% for nonfrail patients. The respective 3-year rates of death or MI were 41% and 17%. After adjustment, frailty [hazard ratio (HR), 4.19 [95% confidence interval (CI), 1.85, 9.51], physical component score of the SF-36 (HR, 1.59; 95% CI, 1.24 to 2.02), and comorbidity, (HR, 1.10; 95% CI, 1.05, 1.16) were associated with mortality. Frailty was associated with mortality/MI (HR, 2.61, 1.52, 4.50). Models with conventional Mayo Clinic risk score had C-statistics of 0.628, 0.573 for mortality and mortality/MI, respectively. Adding frailty, quality of life, and comorbidity, the C-statistic was (0.675, 0.694, 0.671) for mortality and (0.607, 0.587, 0.576) for mortality/MI, respectively. Including frailty, comorbidities and SF-36, conferred a discernible improvement to predict death and death/MI (integrated discrimination improvement, 0.027 and 0.016, and net reclassification improvement of 43% and 18%, respectively). Conclusions— After PCI, frailty, comorbidity and poor quality of life are prevalent and are associated with adverse long-term outcomes. Their inclusion improves the discriminatory ability of the Mayo Clinic risk score derived from the routine cardiovascular risk factors.

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.

Background— Existing models for outcome after percutaneous coronary interventions (PCIs) lack assessment of long-term prognosis. Our goal was to derive 1- and 5-year mortality and mortality/myocardial infarction (MI) risk models for PCI outcomes from simple, easily obtainable clinical and laboratory variables. Methods and Results— Using the Mayo Clinic registry, we analyzed long-term mortality and mortality/MI following PCIs on 9165 unique patients from January 1, 2001, through December 31, 2007. Cox proportional hazards regression was used to model the calculated risk score and major procedural complications. A total of 1243 patients died, and 696 had MI. Separate risk models derived from clinical, procedural, and laboratory characteristics were made for mortality and mortality/MI. Older age, comorbid conditions, low ejection fraction, acute MI, history of smoking, heart failure, hyperlipidemia, 3-vessel disease, procedural failure, ventricular arrhythmia during PCI, and low medication score were predictors of long-term mortality and mortality/MI. Simple integer scores stratified patients into low, moderate, high, and very high risk for subsequent events. Models had adequate goodness of fit, and areas under the receiver operating characteristic curve were 0.786 and 0.728 for mortality and mortality/MI, respectively, indicating good overall discrimination. Bootstrap analysis indicated that the model was not overfit to the available data set. Conclusions— Easily obtainable variables can be combined into a convenient risk scoring system at the time of patient dismissal following PCI to accurately predict long-term mortality and mortality/MI. This model may be useful for providing patients with individualized, evidence-based estimates of long-term risk.

Background— Endothelin (ET-1) is one of the most potent vasoconstrictors and plays a seminal role in the pathogenesis of atherosclerosis. The present study was designed to test the hypothesis that long-term treatment with an endothelin-A (ET A ) receptor antagonist improves coronary endothelial function in patients with early coronary atherosclerosis. Methods and Results— Forty-seven patients with multiple cardiovascular risk factors, nonobstructive coronary artery disease, and coronary endothelial dysfunction were randomized in a double-blind manner to either the ET A receptor antagonist atrasentan (10 mg) or placebo for 6 months. Coronary endothelium-dependent vasodilation was examined by infusing acetylcholine (10 −6 to 10 −4 mol/L) in the left anterior descending coronary artery. N G -monomethyl- l -arginine was administered to a subgroup of patients. Endothelium-independent coronary flow reserve was examined by use of intracoronary adenosine and nitroglycerin. Baseline characteristics and incidence of adverse effects were similar between the 2 groups. There was a significant improvement in percent change of coronary blood flow in response to acetylcholine at 6 months from baseline in the atrasentan group compared with the placebo group (39.67%, 95% confidence interval 23.23% to 68.21%, versus −2.22%, 95% confidence interval −27.37% to 15.28%; P <0.001). No significant difference in the percent change of coronary artery diameter or change in coronary flow reserve was demonstrated. Coronary blood flow, coronary artery diameter, and the effect of N G -monomethyl- l -arginine were similar between the groups at baseline and at 6 months. Conclusions— This study demonstrates that 6-month treatment with atrasentan improves coronary microvascular endothelial function and supports the role of the endogenous endothelin system in the regulation of endothelial function in early atherosclerosis in humans. Clinical Trial Registration Information— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00271492.

Background— Circadian rhythms with regard to time of symptom onset for patients with acute myocardial infarction have been observed, although their relationship to outcomes has been debated. We evaluated these rhythms in patients with ST-elevation myocardial infarction as a function of the 24-hour circadian cycle. Methods and Results— The relationship between onset of symptoms during the 24-hour circadian cycle and prehospital delays from symptom onset to hospital arrival, timeliness of reperfusion, and in-hospital death was assessed in 2143 patients with ST-elevation myocardial infarction presenting from 2004–2008 at 1 of 3 tertiary-care healthcare ST-elevation myocardial infarction systems. There was a significant association between time of onset and the circadian cycle, with the greatest percentage (39%) of patients experiencing onset between 8 am and 3 pm ( P <0.001). Time of onset was associated with prehospital delay and timeliness of reperfusion. Patients with onset from 12 am to 5:59 am had median prehospital delays of 121 minutes versus 70 minutes from 12 pm to 5:59 pm ( P <0.001). Patients with onset time from 12 am to 5:59 am had median door-to-balloon times of 75 minutes versus 60 minutes from 6 am to 11:59 am ( P <0.001). Using multivariable modeling to control for baseline patient characteristics, prehospital delay, and timeliness of reperfusion, there was no significant association between time of symptom onset with in-hospital death. Conclusions— Patients with ST-elevation myocardial infarction exhibit significant circadian patterns in symptom onset, prehospital delay, and timeliness of reperfusion. Patients who develop symptoms from 12 am to 5:59 am present with longer prehospital delays and have longer door-to-balloon times. After multivariable adjustment, there was no significant association between circadian patterns of time of onset and in-hospital death.