John A. House

Association Between Use of Bleeding Avoidance Strategies and Risk of Periprocedural Bleeding Among Patients Undergoing Percutaneous Coronary Intervention

CONTEXT Bleeding complications with percutaneous coronary intervention (PCI) are associated with adverse patient outcomes. The association between the use of bleeding avoidance strategies and post-PCI bleeding as a function of a patients preprocedural risk of bleeding is unknown. OBJECTIVE To describe the use of 2 bleeding avoidance strategies, vascular closure devices and bivalirudin, and associated post-PCI bleeding rates in a nationally representative PCI population. DESIGN, SETTING, AND PATIENTS Analysis of data from 1,522,935 patients undergoing PCI procedures performed at 955 US hospitals participating in the National Cardiovascular Data Registry (NCDR) CathPCI Registry from January 1, 2004, through September 30, 2008. MAIN OUTCOME MEASURE Periprocedural bleeding. RESULTS Bleeding occurred in 30,654 patients (2%). Manual compression, vascular closure devices, bivalirudin, or vascular closure devices plus bivalirudin were used in 35%, 24%, 23%, and 18% of patients, respectively. Bleeding events were reported in 2.8% of patients who received manual compression, compared with 2.1%, 1.6%, and 0.9% of patients receiving vascular closure devices, bivalirudin, and both strategies, respectively (P < .001). Bleeding rates differed by preprocedural risk assessed with the NCDR bleeding risk model (low risk, 0.72%; intermediate risk, 1.73%; high risk, 4.69%). In high-risk patients, use of both strategies was associated with lower bleeding rates (manual compression, 6.1%; vascular closure devices, 4.6%; bivalirudin, 3.8%; vascular closure devices plus bivalirudin, 2.3%; P < .001). This association persisted following adjustment using a propensity-matched and site-controlled model. Use of both strategies was used least often in high-risk patients (14.4% vs 21.0% in low-risk patients, P < .001). CONCLUSIONS In a large national PCI registry, vascular closure devices and bivalirudin were associated with significantly lower bleeding rates, particularly among patients at greatest risk for bleeding. However, these strategies were less often used among higher-risk patients.

Bleeding in Patients Undergoing Percutaneous Coronary Intervention: The Development of a Clinical Risk Algorithm from the National Cardiovascular Data Registry

Background—Bleeding in patients undergoing percutaneous coronary intervention (PCI) is associated with increased morbidity, mortality, length of hospitalization, and cost. We identified baseline clinical characteristics associated with bleeding complications after PCI and developed a simplified, clinically useful algorithm to predict patient risk. Methods and Results—Data were analyzed from 302 152 PCI procedures performed at 440 US centers participating in the National Cardiovascular Data Registry. As defined by the National Cardiovascular Data Registry, bleeding required transfusion, prolonged hospital stay, and/or a drop in hemoglobin >3.0 g/dL from any location, including percutaneous entry site, retroperitoneal, gastrointestinal, genitourinary, and other/unknown location. Bleeding complications occurred in 2.4% of patients. From the best-fitting model consisting of 15 clinical elements associated with post-PCI bleeding in a random 80% training cohort, we developed a parsimonious risk algorithm. Predictors of bleeding included age, gender, previous heart failure, glomerular filtration rate, peripheral vascular disease, no previous PCI, New York Heart Association/Canadian Cardiovascular Society Functional Classification class IV heart failure, ST-elevation myocardial infarction, non–ST-elevation myocardial infarction, and cardiogenic shock. The parsimonious model was validated in the remaining 20% of the population (c-statistic, 0.72) and in clinically relevant subgroups of patients. This simplified model was used to derive a clinical risk algorithm, with larger numbers corresponding with greater risk. In 3 categories, bleeding rates were greater in patients with higher estimates (≤7, 0.7%; 8 to 17, 1.8%; ≥18, 5.1%). Conclusions—This report identifies baseline clinical factors associated with bleeding and proposes a clinically useful algorithm to estimate bleeding risk. This model is potentially actionable in altering therapeutic decision making and improving outcomes in patients undergoing PCI.Background— Bleeding in patients undergoing percutaneous coronary intervention (PCI) is associated with increased morbidity, mortality, length of hospitalization, and cost. We identified baseline clinical characteristics associated with bleeding complications after PCI and developed a simplified, clinically useful algorithm to predict patient risk. Methods and Results— Data were analyzed from 302 152 PCI procedures performed at 440 US centers participating in the National Cardiovascular Data Registry. As defined by the National Cardiovascular Data Registry, bleeding required transfusion, prolonged hospital stay, and/or a drop in hemoglobin >3.0 g/dL from any location, including percutaneous entry site, retroperitoneal, gastrointestinal, genitourinary, and other/unknown location. Bleeding complications occurred in 2.4% of patients. From the best-fitting model consisting of 15 clinical elements associated with post-PCI bleeding in a random 80% training cohort, we developed a parsimonious risk algorithm. Predictors of bleeding included age, gender, previous heart failure, glomerular filtration rate, peripheral vascular disease, no previous PCI, New York Heart Association/Canadian Cardiovascular Society Functional Classification class IV heart failure, ST-elevation myocardial infarction, non–ST-elevation myocardial infarction, and cardiogenic shock. The parsimonious model was validated in the remaining 20% of the population (c-statistic, 0.72) and in clinically relevant subgroups of patients. This simplified model was used to derive a clinical risk algorithm, with larger numbers corresponding with greater risk. In 3 categories, bleeding rates were greater in patients with higher estimates (≤7, 0.7%; 8 to 17, 1.8%; ≥18, 5.1%). Conclusions— This report identifies baseline clinical factors associated with bleeding and proposes a clinically useful algorithm to estimate bleeding risk. This model is potentially actionable in altering therapeutic decision making and improving outcomes in patients undergoing PCI. Received December 22, 2008; accepted April 20, 2009. # CLINICAL PERSPECTIVE {#article-title-2}

Cholesterol oxidation products are sensitive and specific blood-based biomarkers for Niemann-Pick C1 disease

Oxysterols are biomarkers for diagnosis and drug treatment in Niemann-Pick C1 disease. Turning the Tables on Cholesterol A big push in disease research is to identify biochemical markers (biomarkers) in the blood that are early indicators of a disease that is already silently under way. By detecting the disease in its earliest stages, drugs and other therapeutic interventions have the best chance of halting or reversing the course of the disease before major tissue damage has been done. In a new study, Porter and colleagues set out to identify blood biomarkers for Niemann-Pick C1, a childhood neurological disease that is usually fatal. Niemann-Pick C1 disease is caused by mutations in the NPC1 or NPC2 proteins that result in mishandling of cholesterol and lipids in the endolysosomal system of cells. This leads to aberrant deposition of free cholesterol in the central nervous system, the death of neurons, and increasing motor and intellectual impairment, usually resulting in death during adolescence. The early symptoms of the disease are often difficult to distinguish from other childhood diseases, and thus, intervention in the form of a drug such as miglustat often comes too late. This prompted Porter and coworkers to search for possible molecules in the blood that could be used for early diagnosis of the disease and also to monitor the effectiveness of new drugs. On the basis of reports that aberrantly deposited free cholesterol is associated with increased oxidative stress, these investigators reasoned that cholesterol oxidation products (oxysterols) might be the long-sought biomarkers for Niemann-Pick C1 disease. Working in mice lacking the Npc1 gene, the researchers quickly identified two oxysterols that were markedly elevated in the plasma and tissues of the sick mice but not their healthy counterparts. Furthermore, the concentrations of these two oxysterols increased as the disease progressed. Moving into cats carrying an NPC1 mutation, which exhibit similar disease symptoms and progression as human patients, Porter and coworkers were able to decrease elevated concentrations of the two oxysterols and ameliorate disease symptoms by treating the animals with the experimental drug cyclodextrin. But could oxysterols be used as biomarkers in the human disease? The investigators demonstrated that the blood concentrations of two related oxysterol molecules were almost 10 times higher in Niemann-Pick C1 patients than in age-matched healthy controls or those with other diseases such as atherosclerosis or diabetes. Together, these compelling results suggest that the two oxysterol molecules are accurate diagnostic markers of early clinical disease and can be used not only to monitor disease progression but also to demonstrate drug efficacy. Free cholesterol may be at the root of Niemann-Pick C1 disease, but now, there is a way to turn the tables on cholesterol by using its oxidation products to diagnose and treat the disease in its earliest stages. Niemann-Pick type C1 (NPC1) disease is a rare progressive neurodegenerative disorder characterized by accumulation of cholesterol in the endolysosomes. Previous studies implicating oxidative stress in NPC1 disease pathogenesis raised the possibility that nonenzymatic formation of cholesterol oxidation products could serve as disease biomarkers. We measured these metabolites in the plasma and tissues of the Npc1−/− mouse model and found several cholesterol oxidation products that were elevated in Npc1−/− mice, were detectable before the onset of symptoms, and were associated with disease progression. Nonenzymatically formed cholesterol oxidation products were similarly increased in the plasma of all human NPC1 subjects studied and delineated an oxysterol profile specific for NPC1 disease. This oxysterol profile also correlated with the age of disease onset and disease severity. We further show that the plasma oxysterol markers decreased in response to an established therapeutic intervention in the NPC1 feline model. These cholesterol oxidation products are robust blood-based biochemical markers for NPC1 disease that may prove transformative for diagnosis and treatment of this disorder, and as outcome measures to monitor response to therapy.

Chronic Total Occlusion Angioplasty in the United States

Coronary chronic total occlusions (CTOs) are commonly encountered complex lesions identified in 15% of all patients referred for coronary angiography. Chronic total occlusion remains the most powerful predictor of referral for coronary bypass surgery. The benefits of CTO percutaneous coronary intervention (PCI) include symptom relief, improved left ventricular function, and potentially a survival advantage associated with success when compared with failed CTO-PCI. Data from the NCDR (National Cardiovascular Data Registry) suggest that CTO-PCI attempt rates in the U.S. have not changed over the past 5 years despite significant advances in techniques and technology, some of which we review here. Additionally, these data highlight a major disparity in attempt rates based on operator PCI volume. Remaining barriers to attempting CTO-PCI in the U.S. include operator inexperience, the perception of increased risk of CTO-PCI, and financial disincentives to operators and hospitals. To overcome operator inexperience, participation in CTO clubs, the invitation of guest operators, and a dedicated CTO day can be implemented at institutions committed to learning advanced CTO-PCI techniques so that operators can overcome the barriers and offer patients access to percutaneous therapy when it is clinically indicated.

Improvement in Survival Following Successful Percutaneous Coronary Intervention of Coronary Chronic Total Occlusions: Variability by Target Vessel

OBJECTIVES This study compared the survival benefit of opening a chronic total occlusion (CTO) of the left anterior descending (LAD), left circumflex (LCX), or right coronary artery (RCA). BACKGROUND Previous analyses demonstrate improved survival following successful percutaneous coronary intervention (PCI) for CTO. METHODS Eligible patients underwent attempted CTO PCI in a single vessel. Procedural success rates were calculated for each vessel. The primary end point was survival at 5 years, compared across target vessel groups stratified by procedural success. RESULTS There were 2,608 patients included. The LAD was the target vessel in 936 (36%), the LCX in 682 (26%), and the RCA in 990 (38%) patients. Angiographic success rates for LAD were 77%, LCX 76%, and RCA 72%. Baseline demographics and comorbidities were well matched, though there were significantly more males in the LCX compared with LAD or RCA groups (80% vs. 75% and 73%, respectively, p = 0.005). Procedural success compared with failure was associated with improved 5-year survival in the LAD (88.9% vs. 80.2%, p < 0.001) group, but not in the LCX (86.1% vs. 82.1%, p = 0.21) and RCA groups (87.7% vs. 84.9%, p = 0.23). In multivariable analysis, CTO PCI success in the LAD group remained associated with decreased mortality risk (HR: 0.61, 95% CI: 0.42 to 0.89). CONCLUSIONS The data suggest that PCI for CTO of the LAD, but not LCX or RCA, is associated with improved long-term survival. This information may assist in selecting patients for attempted CTO PCI.

Cardiovascular safety of liraglutide assessed in a patient-level pooled analysis of phase 2—3 liraglutide clinical development studies

We assessed the cardiovascular safety of liraglutide, a glucagon-like peptide-1 receptor agonist, using existing clinical data. Patient-level results from all completed phase 2 and 3 studies from the liraglutide clinical development programme were pooled to determine rates of major adverse cardiovascular events (MACE): cardiovascular death, myocardial infarction, stroke. MACE were identified by querying the study database using Medical Dictionary for Regulatory Activities (MedDRA) terms combined with serious adverse events recorded by study investigators. Broad, narrow, and custom groups of MedDRA queries were used. Candidate events from each query were independently adjudicated post hoc. In 15 studies (6638 patients; 4257 liraglutide treated), there were 114 patients with MACE identified using the broad MedDRA query. Of these, 44 were classified as serious adverse events and 39 were adjudicated as MACE. The incidence ratio for adjudicated broad/serious MACE associated with liraglutide was 0.73 (95% CI 0.38—1.41) versus all comparator drugs (metformin, glimepiride, rosiglitazone, insulin glargine, placebo), within cardiovascular safety limits defined by the United States Food & Drug Administration for diabetes therapies under current investigation.

Serum Trimethylamine-N-Oxide is Elevated in CKD and Correlates with Coronary Atherosclerosis Burden

Trimethlyamine-N-oxide (TMAO) was recently identified as a promoter of atherosclerosis. Patients with CKD exhibit accelerated development of atherosclerosis; however, no studies have explored the relationship between TMAO and atherosclerosis formation in this group. This study measured serum concentrations and urinary excretion of TMAO in a CKD cohort (n=104), identified the effect of renal transplant on serum TMAO concentration in a subset of these patients (n=6), and explored the cross-sectional relationship between serum TMAO and coronary atherosclerosis burden in a separate CKD cohort (n=220) undergoing coronary angiography. Additional exploratory analyses examined the relationship between baseline serum TMAO and long-term survival after coronary angiography. Serum TMAO concentrations demonstrated a strong inverse association with eGFR (r(2)=0.31, P<0.001). TMAO concentrations were markedly higher in patients receiving dialysis (median [interquartile range], 94.4 μM [54.8-133.0 μM] for dialysis-dependent patients versus 3.3 μM [3.1-6.0 μM] for healthy controls; P<0.001); whereas renal transplantation resulted in substantial reductions in TMAO concentrations (median [min-max] 71.2 μM [29.2-189.7 μM] pretransplant versus 11.4 μM [8.9-20.2 μM] post-transplant; P=0.03). TMAO concentration was an independent predictor for coronary atherosclerosis burden (P=0.02) and predicted long-term mortality independent of traditional cardiac risk factors (hazard ratio, 1.26 per 10 μM increment in TMAO concentration; 95% confidence interval, 1.13 to 1.40; P<0.001). In conclusion, serum TMAO concentrations substantially increase with decrements in kidney function, and this effect is reversed by renal transplantation. Increased TMAO concentrations correlate with coronary atherosclerosis burden and may associate with long-term mortality in patients with CKD undergoing coronary angiography.

Risk of Restenosis and Health Status Outcomes for Patients Undergoing Percutaneous Coronary Intervention Versus Coronary Artery Bypass Graft Surgery

Background—Previous comparisons of percutaneous coronary interventions (PCIs) and coronary artery bypass graft (CABG) surgery have demonstrated similar survival but have also generally found better health status outcomes (symptoms, function, and quality of life) with CABG. The principal limitation of PCI has been the occurrence of restenosis. No previous studies comparing the health status outcomes of PCI and CABG have examined differences in these outcomes as a function of patients’ preprocedural risk for restenosis. Methods and Results—We examined the health status outcomes, using the Seattle Angina Questionnaire (SAQ), among 1459 consecutive patients (1027 treated with PCI and 432, with CABG), stratified by their risk for restenosis. In multivariable-adjusted, linear regression analyses, no differences in 1-year angina or quality of life were observed among the 37.4% of patients at low risk for restenosis. However, among the 46.7% at intermediate risk for restenosis, 1-year health status scores were moderately better after CABG surgery compared with PCI (difference in SAQ angina frequency scores favoring CABG=6.1±1.7 points, P=0.0003; difference in SAQ quality of life=5.8±1.6 points, P=0.0004). Even larger differences in 1-year outcomes favoring CABG surgery were observed in patients at high risk for restenosis (SAQ angina frequency difference=10.8±4.2, P=0.01; SAQ quality of life difference=10.8±3.9, P=0.006). Conclusions—The relative health status benefits of CABG surgery compared with PCI increase as the risk of restenosis increases. Although selecting CABG or PCI is complex, preprocedural restenosis risk should be considered. It should also be tested as a means for considering drug-eluting as opposed to bare metal stents in PCI.

Diabetes Duration Is Associated With Increased Thin-Cap Fibroatheroma Detected by Intravascular Ultrasound With Virtual Histology

Background—Coronary plaque classified as thin-cap fibroatheroma (TCFA) is believed to be associated with plaque rupture and coronary heart disease–related events. Although an association between duration of diabetes and increased coronary heart disease risk has been demonstrated, the relationship between TCFA and diabetes duration is unknown. Methods and Results—Prospective registry of diabetic patients undergoing diagnostic coronary angiography and intravascular ultrasound (IVUS) enrolled in a diabetic gene and biomarker banking registry. Plaque composition in the most diseased 10-mm segment of a single coronary artery was assessed using IVUS virtual histology and was classified by phenotype as IVUS-defined adaptive intimal thickening, pathological intimal thickening, TCFA, fibroatheroma, or fibrocalcific. Patients (n=54) were stratified by duration of diabetes (<10 or ≥10 years). Patients with diabetes ≥10 years were older, less likely to have a history of tobacco use, had higher total cholesterol levels, and were more likely to be treated with insulin compared with patients with diabetes <10 years. Longer duration of diabetes was associated with greater plaque burden in the most diseased 10-mm segment (60.4% [53.4% to 66.8%] versus 50.2% [47.7% to 58.4%], P=0.008). The proportion of IVUS-defined TCFA in the ≥10-year group was greater than the <10-year group (54.4% [11.6% to 77.5%] versus 10.8% [0.0% to 26.1%], P=0.009). This association persisted after adjustment for multiple comparisons, clinical characteristics, and diabetes treatment. Conclusions—In this cohort, longer duration of diabetes was associated with IVUS-defined TCFA, a plaque phenotype associated with risk of rupture and coronary heart disease events. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT00428961.

The effect of intensive glucose control on all-cause and cardiovascular mortality, myocardial infarction and stroke in persons with type 2 diabetes mellitus: a systematic review and meta-analysis

We performed a meta-analysis of studies evaluating the effect of intensive glucose control on major adverse cardiovascular events in patients with type 2 diabetes from 1990 to 2009. A search of the published literature and the Cochran Central Register for Controlled Trials was performed using pre-specified inclusion criteria consisting of randomised controlled trials evaluating intensive glycaemic control and reporting the individual endpoints of all-cause mortality, non-fatal myocardial infarction, and non-fatal stroke. Incident rate ratios for these endpoints were calculated using standard meta-analytic techniques of pooled data from eligible trials. Six reports from four randomised trials including 27,544 patients met the pre-specified inclusion criteria. Mean follow-up was 5.4 years; haemoglobin A1C at study end was 6.6% vs. 7.4% in patients randomised to intensive compared with conventional glucose control. Intensive glucose control did not affect the incident rate ratio for all-cause mortality (1.01, 95% confidence interval 0.86—1.18, p=0.54) or stroke (1.02, 95% confidence interval 0.88—1.20, p=0.62). However, there was a statistically significant 14% reduction in non-fatal myocardial infarction in patients randomised to intensive glucose control (0.86, 95% confidence interval 0.77—0.97, p=0.015). Although intensification of glucose control did not affect mortality or non-fatal stroke, the risk for non-fatal myocardial infarction was significantly reduced in patients with type 2 diabetes.