Holmes, David R.

Background— The benefit of primary percutaneous coronary interventions (P-PCI) for patients with ST-elevation myocardial infarction (STEMI) has been well documented. However, controversy still exists as to whether PCI should be expanded to hospitals without coronary artery bypass graft surgery. Methods and Results— Patients who were discharged after PCI for STEMI between January 1, 2003, and December 12, 2006, in P-PCI centers (hospitals with no coronary artery bypass graft surgery, and PCI only for patients with STEMI) were propensity matched with patients in full service centers, and mortality and subsequent revascularization rates were compared. For patients undergoing PCI, there were no differences for in-hospital/30-day mortality (2.3% for P-PCI centers versus 1.9% for full service centers [ P =0.40]), emergency coronary artery bypass graft surgery immediately after PCI (0.06% versus 0.35%, P =0.06), 3-year mortality (7.1% versus 5.9%, P =0.07), or 3-year subsequent revascularization (23.8% versus 21.5%, P =0.52). P-PCI centers had a lower same/next day coronary artery bypass graft rate (0.23% versus 0.69%, P =0.046) and higher repeat target vessel PCI rates (12.1% versus 9.0%, P =0.003). For patients with STEMI who did not undergo PCI, P-PCI centers had higher in-hospital mortality (28.5% versus 22.3%; adjusted odds ratio, 1.38; 95% CI, 1.10 to 1.75). Conclusions— No differences between P-PCI centers and full service centers were found in in-hospital/30-day mortality, the need for emergency surgery, 3-year mortality or subsequent revascularization, but P-PCI centers had higher repeat target vessel PCI rates and higher mortality rates for patients who did not undergo PCI. P-PCI centers should be monitored closely, including the monitoring of patients with STEMI who did not undergo PCI.

Background— American College of Cardiology/American Heart Association guidelines recommend a door-to-balloon time (DTB) <90 minutes for nontransferred patients with ST-elevation myocardial infarction (STEMI) who undergo primary percutaneous coronary intervention. Systems of care to achieve and sustain this DTB performance over several years have not been previously reported. Methods and Results— The Mayo Clinic STEMI protocol was implemented in April 2004 and included activation of the cardiac catheterization laboratory by the emergency medicine physician; a single call system to activate the catheterization laboratory; catheterization laboratory staff arrival within 20 to 30 minutes of activation; and real-time performance feedback within 24 to 48 hours. Data were collected on nontransferred STEMI patients. The preimplementation group (June 2002 to March 2004) comprised 96 patients with a median DTB of 97 (interquartile range, 82, 130) minutes, and 40% had a DTB <90 minutes. The postimplementation group (May 2004 to March 2008) comprised 322 patients with a median DTB of 67 (interquartile range, 55, 82) minutes, and 81% had a DTB <90 minutes. Postimplementation DTB was significantly shorter than preimplementation DTB ( P <0.001). In the 4-year follow-up after protocol implementation, the DTB performance remained stable over time ( P =0.41). Conclusions— The Mayo Clinic STEMI protocol implemented strategies to reduce DTB for nontransferred patients with STEMI. DTB was significantly reduced, and the results were sustained over the 4-year follow-up period. Our experience demonstrates the effectiveness and durability of process changes targeting timeliness of primary percutaneous coronary intervention.

A significant proportion of patients with ST-elevation myocardial infarction have persistent impairment of microvascular blood flow despite successful reperfusion of epicardial vessels. Microvascular dysfunction has been associated with larger infarct size, increased predisposition to ventricular arrhythmias, heart failure, cardiogenic shock, recurrent myocardial infarction, and death. It remains unclear whether this association is of direct mechanistic significance or whether the microcirculatory injury is an epiphenomenon and a manifestation of greater ischemic insult to the myocardium. Although several potential mechanisms have been proposed for the microvascular dysfunction, distal microembolization during mechanical reperfusion is likely to be an important contributor. Consequently, there has been increasing interest in the concept of adjunctive mechanical thrombectomy to improve outcomes in primary percutaneous coronary intervention. Until recently, randomized trials of thrombectomy and distal protection devices during primary percutaneous coronary intervention have provided conflicting results with no definitive evidence for efficacy. The recently published Thrombus Aspiration During Percutaneous Coronary Intervention in Acute Myocardial Infarction Study has rekindled the interest in this area. This trial is the largest randomized study of a thrombectomy device published to date and demonstrates that adjunctive treatment with aspiration thrombectomy during primary percutaneous coronary intervention improves surrogate and clinical end points. The aim of the present report is to review the evidence to date on the role of mechanical thrombectomy and embolic protection in native coronary arteries during primary percutaneous coronary intervention.

Background— Temporal trends and contemporary data characterizing the impact of patient age on in-hospital outcomes of percutaneous coronary interventions are lacking. We sought to determine the importance of age by assessing the in-hospital mortality of stratified age groups in the National Cardiovascular Data Registry. Methods and Results— In-hospital mortality after percutaneous coronary intervention on 1 410 069 patients was age stratified into 4 groups—group 1 (age <40, n=25 679), group 2 (40 to 59, n=496 204), group 3 (60 to 79, n=732 574), and group 4 (≥80, n=155 612)—admitted from January 1, 2001, to December 31, 2006. Overall in-hospital mortality was 1.22%; in-hospital mortality was 0.60%, 0.59%, 1.26%, and 3.16% in groups 1 to 4, respectively, P <0.0001. Overall temporal improvement per calendar year in the adjusted in-hospital mortality after percutaneous coronary intervention was noted in most groups; however, this finding was significant only in the 2 older age groups, group 3 (odds ratio, 0.94; 95% CI, 0.92 to 0.96) and group 4 (odds ratio, 0.95; 95% CI, 0.92 to 0.97). The absolute mortality reduction was greatest in the most elderly group, those over the age of 80 years. Conclusions— In-hospital mortality after percutaneous coronary intervention has fallen for all age groups over the past 6 years. However, the largest absolute reduction was seen among patients 80 years of age or older.

September 2007 marked the 30-year anniversary of the first human percutaneous coronary intervention, an index event that changed the course of modern-day cardiovascular care. Before that first procedure, adult invasive cardiology focused on diagnostic angiography as well as hemodynamic assessment of structural heart disease. Since that initial procedure, percutaneous coronary intervention has become the most frequently performed coronary revascularization procedure worldwide. Several factors have been responsible for this dramatic paradigm shift, the most prominent being identification of opportunities for technical improvement and the application of innovation and investigation in concert with colleagues, professional societies, and industry. These approaches will continue to be of paramount importance as new technologies are brought to bear on an increasingly broader group of patients with cardiovascular disease.

Background— Myonecrosis after percutaneous coronary intervention (PCI) has been correlated with a worse prognosis, but controversy exists about the clinical significance and potential mechanisms for the association. The aim of this study was to evaluate the relative impact of preprocedural and postprocedural cardiac troponin T (cTnT) levels on survival rate after PCI. Methods and Results— We evaluated 5487 patients from the Mayo Clinic registry who required nonemergency PCI, and we examined the relationship between periprocedural cTnT levels, with the 99th percentile cutoff value used for normal (<0.01 ng/mL), and outcomes. The patients were divided into 3 groups: normal preprocedural and postprocedural cTnT levels (no myonecrosis), normal preprocedural but elevated postprocedural cTnT levels (PCI-related myonecrosis), and abnormal preprocedural cTnT. The 30-day death rates were 0.1%, 0.6%, and 2.3%, respectively, in the 3 groups. In a multivariable model, an abnormal pre-PCI cTnT level (hazard ratio 9.66 [2.30–40.57]; P =0.002), and PCI-related myonecrosis (4.71 [1.02–21.83]; P =0.048) were independent predictors of 30-day mortality. Over a median follow-up of 28 months, an abnormal pre-PCI cTnT level (hazard ratio 1.79 [1.35–2.39]; P <0.001) independently predicted death, but the occurrence of PCI-related myonecrosis did not. A postprocedural elevation in creatine kinase MB fraction was not an independent predictor of long-term risk of death (0.912 [0.70–1.19]; P =0.5). Conclusions— A preprocedural cTnT level >0.01 is a powerful independent predictor of prognosis after PCI and is of greater prognostic significance than the postprocedural biomarker levels. PCI-related myonecrosis occurs frequently and predicts short-term but not long-term risk of death.

Endothelin plays an important role in the pathogenesis of atherosclerosis. The aim of the study was to evaluate the safety and hemodynamic and metabolic responses to 6 months treatment with atrasentan, the selective endothelin-A receptor antagonist. Seventy-two patients with multiple cardiovascular risk factors and nonobstructive coronary artery disease on coronary angiogram were randomly assigned in a double-blind manner to atrasentan or placebo. Mean aortic blood pressure decreased from 92±10 to 80±10 mm Hg ( P <0.001) in the atrasentan group and did not change in the placebo group (93±10 and 92±11 mm Hg; P =0.84). The difference between the groups was significant ( P <0.001). No effect on heart rate was observed. In a subgroup of patients not treated with angiotensin-converting enzyme inhibitor, creatinine level decreased in the atrasentan versus the placebo group ( P =0.011). Fasting glucose ( P =0.026), glycosylated hemoglobin level ( P =0.041), triglyceride l ( P =0.013), lipoprotein-A ( P =0.046), and uric acid levels ( P =0.048) decreased significantly in the atrasentan group compared with the placebo group. No progression of angiographic coronary disease was observed. The most common adverse effects with atrasentan were nasal stuffiness, headache, and edema. In conclusion, 6 months of treatment with atrasentan results in a reduction of blood pressure and improvement in glucose and lipid metabolism. These findings suggest the beneficial role of atrasentan in the treatment of hypertension and metabolic syndrome.