Aspirin and Cardiovascular Risk in Individuals With Elevated Lipoprotein(a): The Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Effective therapies for reducing cardiovascular disease (CVD) risk in people with elevated lipoprotein(a) are lacking, especially for primary prevention. Because of the potential association of lipoprotein(a) with thrombosis, we evaluated the relationship between aspirin use and CVD events in people with elevated lipoprotein(a).

METHODS AND RESULTS

We used data from the MESA (Multi-Ethnic Study of Atherosclerosis), a prospective cohort study of individuals free of baseline cardiovascular disease. Due to potential confounding by indication, we matched aspirin users to nonusers using a propensity score based on CVD risk factors. We then evaluated the association between aspirin use and coronary heart disease (CHD) events (CHD death, nonfatal myocardial infarction) stratified by baseline lipoprotein(a) level (threshold of 50 mg/dL) using Cox proportional hazards models with adjustment for CVD risk factors. After propensity matching, the study cohort included 2183 participants, including 1234 (57%) with baseline aspirin use and 423 (19%) with lipoprotein(a) >50 mg/dL. Participants with lipoprotein(a) >50 mg/dL had a higher burden of CVD risk factors, more frequent aspirin use (61.7% versus 55.3%, P=0.02), and higher rate of incident CHD events (13.7% versus 8.9%, P<0.01). Aspirin was associated with a significant reduction in CHD events among those with elevated lipoprotein(a) (hazard ratio, 0.54 [95% CI, 0.32-0.94]; P=0.03). Those with lipoprotein(a) >50 mg/dL and aspirin use had similar CHD risk as those with lipoprotein(a) ≤50 mg/dL regardless of aspirin use.

CONCLUSIONS

Aspirin use was associated with a significantly lower risk for CHD events in participants with lipoprotein(a) >50 mg/dL without baseline CVD. The results of this observational propensity-matched study require confirmation in studies with randomization of aspirin use.

Pulmonary Artery Catheter Use and Mortality in the Cardiac Intensive Care Unit

BACKGROUND

The appropriate use of pulmonary artery catheters (PACs) in critically ill cardiac patients remains debated.

OBJECTIVES

The authors aimed to characterize the current use of PACs in cardiac intensive care units (CICUs) with attention to patient-level and institutional factors influencing their application and explore the association with in-hospital mortality.

METHODS

The Critical Care Cardiology Trials Network is a multicenter network of CICUs in North America. Between 2017 and 2021, participating centers contributed annual 2-month snapshots of consecutive CICU admissions. Admission diagnoses, clinical and demographic data, use of PACs, and in-hospital mortality were captured.

RESULTS

Among 13,618 admissions at 34 sites, 3,827 were diagnosed with shock, with 2,583 of cardiogenic etiology. The use of mechanical circulatory support and heart failure were the patient-level factors most strongly associated with a greater likelihood of the use of a PAC (OR: 5.99 [95% CI: 5.15-6.98]; P < 0.001 and OR: 3.33 [95% CI: 2.91-3.81]; P < 0.001, respectively). The proportion of shock admissions with a PAC varied significantly by study center ranging from 8% to 73%. In analyses adjusted for factors associated with their placement, PAC use was associated with lower mortality in all shock patients admitted to a CICU (OR: 0.79 [95% CI: 0.66-0.96]; P = 0.017).

CONCLUSIONS

There is wide variation in the use of PACs that is not fully explained by patient level-factors and appears driven in part by institutional tendency. PAC use was associated with higher survival in cardiac patients with shock presenting to CICUs. Randomized trials are needed to guide the appropriate use of PACs in cardiac critical care.

Demographics, Care Patterns, and Outcomes of Patients Admitted to Cardiac Intensive Care Units: The Critical Care Cardiology Trials Network Prospective North American Multicenter Registry of Cardiac Critical Illness

Importance

Single-center and claims-based studies have described substantial changes in the landscape of care in the cardiac intensive care unit (CICU). Professional societies have recommended research to guide evidence-based CICU redesigns.

Objective

To characterize patients admitted to contemporary, advanced CICUs.

Design, Setting, and Participants

This study established the Critical Care Cardiology Trials Network (CCCTN), an investigator-initiated multicenter network of 16 advanced, tertiary CICUs in the United States and Canada. For 2 months in each CICU, data for consecutive admissions were submitted to the central data coordinating center (TIMI Study Group). The data were collected and analyzed between September 2017 and 2018.

Main Outcomes and Measures

Demographics, diagnoses, management, and outcomes.

Results

Of 3049 participants, 1132 (37.1%) were women, 797 (31.4%) were individuals of color, and the median age was 65 years (25th and 75th percentiles, 55-75 years). Between September 2017 and September 2018, 3310 admissions were included, among which 2557 (77.3%) were for primary cardiac problems, 337 (10.2%) for postprocedural care, 253 (7.7%) for mixed general and cardiac problems, and 163 (4.9%) for overflow from general medical ICUs. When restricted to the initial 2 months of medical CICU admissions for each site, the primary analysis population included 3049 admissions with a high burden of noncardiovascular comorbidities. The top 2 CICU admission diagnoses were acute coronary syndrome (969 [31.8%]) and heart failure (567 [18.6%]); however, the proportion of acute coronary syndrome was highly variable across centers (15%-57%). The primary indications for CICU care included respiratory insufficiency (814 [26.7%]), shock (643 [21.1%]), unstable arrhythmia (521 [17.1%]), and cardiac arrest (265 [8.7%]). Advanced CICU therapies or monitoring were required for 1776 patients (58.2%), including intravenous vasoactive medications (1105 [36.2%]), invasive hemodynamic monitoring (938 [30.8%]), and mechanical ventilation (652 [21.4%]). The overall CICU mortality rate was 8.3% (95% CI, 7.3%-9.3%). The CICU indications that were associated with the highest mortality rates were cardiac arrest (101 [38.1%]), cardiogenic shock (140 [30.6%]), and the need for renal replacement therapy (51 [34.5%]). Notably, patients admitted solely for postprocedural observation or frequent monitoring had a mortality rate of 0.2% to 0.4%.

Conclusions and Relevance

In a contemporary network of tertiary care CICUs, respiratory failure and shock predominated indications for admission and carried a poor prognosis. While patterns of practice varied considerably between centers, a substantial, low-risk population was identified. Multicenter collaborative networks, such as the CCCTN, could be used to help redesign cardiac critical care and to test new therapeutic strategies.

Incidence, underlying conditions, and outcomes of patients receiving acute renal replacement therapies in tertiary cardiac intensive care units: An analysis from the Critical Care Cardiology Trials Network Registry

BACKGROUND

The prevalence of renal disease in cardiac intensive care units (CICUs) is increasing, but little is known about the utilization, concurrent therapies, and outcomes of patients requiring acute renal replacement therapy (RRT) in this specialized environment.

METHODS

In the Critical Care Cardiology Trials Network, 16 centers submitted data on CICU admissions including acute RRT (defined as continuous renal replacement therapy and/or acute intermittent dialysis).

RESULTS

Among 2,985 admissions, 178 (6.0%; interhospital range 1.0%-16.0%) received acute RRT. Patients receiving RRT, versus not, were more commonly admitted for cardiogenic shock (15.7% vs 4.2%, P < .01), cardiac arrest (9.6% vs 3.7%, P < .01), and acute general medical diagnoses (10.7% vs 5.8%, P < .01), whereas acute coronary syndromes (16.9% vs 32.1%, P < .01) were less frequent. Variables independently associated with acute RRT included diabetes, heart failure, liver disease, severe valvular disease, shock, cardiac arrest, hypertension, and younger age. In patients receiving acute RRT, versus not, advanced therapies including mechanical ventilation (55.6% vs 18.0%), vasoactive support (73.0% vs 35.2%), invasive hemodynamic monitoring (59.6% vs 29.2%), and mechanical circulatory support (27.5% vs 8.4%) were more common. Acute RRT was associated with higher in-hospital mortality (42.1% vs 9.3%, adjusted odds ratio 3.74, 95% CI, 2.52-5.53) and longer median length of stay (10.0 vs 5.3 days, P < .01). In conclusion, acute RRT in contemporary CICUs was associated with the provision of other advanced therapies and lower survival.

CONCLUSIONS

These data underscore the risks associated with the provision of renal support in patients with primary cardiovascular problems and the need to develop standardized indications and potential futility measures in this specialized population.

Association between residential greenness and exposure to volatile organic compounds

Residential proximity to vegetation and plants is associated with many health benefits, including reduced risk of cardiovascular disease, diabetes and mental stress. Although the mechanisms by which proximity to greenness affects health remain unclear, plants have been shown to remove particulate air pollution. However, the association between residential-area vegetation and exposure to volatile organic chemicals (VOCs) has not been investigated. We recruited a cohort of 213 non-smoking individuals and estimated peak, cumulative, and contemporaneous greenery using satellite-derived normalized difference vegetation index (NDVI) near their residence. We found that the urinary metabolites of exposure to VOCs - acrolein, acrylamide, acrylonitrile, benzene, 1-bromopropane, propylene oxide were inversely associated (7-31% lower) with 0.1 higher peak NDVI values within 100 m radius of the participants' home. These associations were significant at radii ranging from 25 to 300 m. Strongest associations were observed within a 200 m radius, where VOC metabolites were 22% lower per 0.1 unit higher NDVI. Of the 18 measured urinary metabolites, 7 were positively associated with variation of greenness within a 200 m radius of homes. The percent of tree canopy and street trees around participants' residence were less strongly associated with metabolite levels. The associations between urinary VOC metabolites and residential NDVI values were stronger in winter than in summer, and in participants who were more educated, White, and those who lived close to areas of high traffic. These findings suggest high levels of residential greenness are associated with lower VOC exposure, particularly in winter.

Cardiovascular injury induced by tobacco products: assessment of risk factors and biomarkers of harm. A Tobacco Centers of Regulatory Science compilation

Although substantial evidence shows that smoking is positively and robustly associated with cardiovascular disease (CVD), the CVD risk associated with the use of new and emerging tobacco products, such as electronic cigarettes, hookah, and heat-not-burn products, remains unclear. This uncertainty stems from lack of knowledge on how the use of these products affects cardiovascular health. Cardiovascular injury associated with the use of new tobacco products could be evaluated by measuring changes in biomarkers of cardiovascular harm that are sensitive to the use of combustible cigarettes. Such cardiovascular injury could be indexed at several levels. Preclinical changes contributing to the pathogenesis of disease could be monitored by measuring changes in systemic inflammation and oxidative stress, organ-specific dysfunctions could be gauged by measuring endothelial function (flow-mediated dilation), platelet aggregation, and arterial stiffness, and organ-specific injury could be evaluated by measuring endothelial microparticles and platelet-leukocyte aggregates. Classical risk factors, such as blood pressure, circulating lipoproteins, and insulin resistance, provide robust estimates of risk, and subclinical disease progression could be followed by measuring coronary artery Ca2+ and carotid intima-media thickness. Given that several of these biomarkers are well-established predictors of major cardiovascular events, the association of these biomarkers with the use of new and emerging tobacco products could be indicative of both individual and population-level CVD risk associated with the use of these products. Differential effects of tobacco products (conventional vs. new and emerging products) on different indexes of cardiovascular injury could also provide insights into mechanisms by which they induce cardiovascular harm.

Association Between Residential Greenness and Cardiovascular Disease Risk

Background Exposure to green vegetation has been linked to positive health, but the pathophysiological processes affected by exposure to vegetation remain unclear. To study the relationship between greenness and cardiovascular disease, we examined the association between residential greenness and biomarkers of cardiovascular injury and disease risk in susceptible individuals. Methods and Results In this cross-sectional study of 408 individuals recruited from a preventive cardiology clinic, we measured biomarkers of cardiovascular injury and risk in participant blood and urine. We estimated greenness from satellite-derived normalized difference vegetation index ( NDVI ) in zones with radii of 250 m and 1 km surrounding the participants' residences. We used generalized estimating equations to examine associations between greenness and cardiovascular disease biomarkers. We adjusted for residential clustering, demographic, clinical, and environmental variables. In fully adjusted models, contemporaneous NDVI within 250 m of participant residence was inversely associated with urinary levels of epinephrine (-6.9%; 95% confidence interval, -11.5, -2.0/0.1 NDVI ) and F2-isoprostane (-9.0%; 95% confidence interval, -15.1, -2.5/0.1 NDVI ). We found stronger associations between NDVI and urinary epinephrine in women, those not on β-blockers, and those who had not previously experienced a myocardial infarction. Of the 15 subtypes of circulating angiogenic cells examined, 11 were inversely associated (8.0-15.6% decrease/0.1 NDVI ), whereas 2 were positively associated (37.6-45.8% increase/0.1 NDVI ) with contemporaneous NDVI . Conclusions Independent of age, sex, race, smoking status, neighborhood deprivation, statin use, and roadway exposure, residential greenness is associated with lower levels of sympathetic activation, reduced oxidative stress, and higher angiogenic capacity.

Residential Proximity to Major Roadways Is Associated With Increased Levels of AC133+ Circulating Angiogenic Cells

OBJECTIVES

Previous studies have shown that residential proximity to a roadway is associated with increased cardiovascular disease risk. Yet, the nature of this association remains unclear, and its effect on individual cardiovascular disease risk factors has not been assessed. The objective of this study was to determine whether residential proximity to roadways influences systemic inflammation and the levels of circulating angiogenic cells.

APPROACH AND RESULTS

In a cross-sectional study, cardiovascular disease risk factors, blood levels of C-reactive protein, and 15 antigenically defined circulating angiogenic cell populations were measured in participants (n=316) with moderate-to-high cardiovascular disease risk. Attributes of roadways surrounding residential locations were assessed using geographic information systems. Associations between road proximity and cardiovascular indices were analyzed using generalized linear models. Close proximity (<50 m) to a major roadway was associated with lower income and higher rates of smoking but not C-reactive protein levels. After adjustment for potential confounders, the levels of circulating angiogenic cells in peripheral blood were significantly elevated in people living in close proximity to a major roadway (CD31(+)/AC133(+), AC133(+), CD34(+)/AC133(+), and CD34(+)/45(dim)/AC133(+) cells) and positively associated with road segment distance (CD31(+)/AC133(+), AC133(+), and CD34(+)/AC133(+) cells), traffic intensity (CD31(+)/AC133(+) and AC133(+) cells), and distance-weighted traffic intensity (CD31(+)/34(+)/45(+)/AC133(+) cells).

CONCLUSIONS

Living close to a major roadway is associated with elevated levels of circulating cells positive for the early stem marker AC133(+). This may reflect an increased need for vascular repair. Levels of these cells in peripheral blood may be a sensitive index of cardiovascular injury because of residential proximity to roadways.

Acrolein exposure is associated with increased cardiovascular disease risk

Background

Acrolein is a reactive aldehyde present in high amounts in coal, wood, paper, and tobacco smoke. It is also generated endogenously by lipid peroxidation and the oxidation of amino acids by myeloperoxidase. In animals, acrolein exposure is associated with the suppression of circulating progenitor cells and increases in thrombosis and atherogenesis. The purpose of this study was to determine whether acrolein exposure in humans is also associated with increased cardiovascular disease (CVD) risk.

Methods and Results

Acrolein exposure was assessed in 211 participants of the Louisville Healthy Heart Study with moderate to high (CVD) risk by measuring the urinary levels of the major acrolein metabolite—3‐hydroxypropylmercapturic acid (3‐HPMA). Generalized linear models were used to assess the association between acrolein exposure and parameters of CVD risk, and adjusted for potential demographic confounders. Urinary 3‐HPMA levels were higher in smokers than nonsmokers and were positively correlated with urinary cotinine levels. Urinary 3‐HPMA levels were inversely related to levels of both early (AC133⁺) and late (AC133⁻) circulating angiogenic cells. In smokers as well as nonsmokers, 3‐HPMA levels were positively associated with both increased levels of platelet–leukocyte aggregates and the Framingham Risk Score. No association was observed between 3‐HPMA and plasma fibrinogen. Levels of C‐reactive protein were associated with 3‐HPMA levels in nonsmokers only.

Conclusions

Regardless of its source, acrolein exposure is associated with platelet activation and suppression of circulating angiogenic cell levels, as well as increased CVD risk.

Relation of hepatic steatosis to atherogenic dyslipidemia

Hepatic steatosis is closely associated with the metabolic syndrome. We assessed for an independent association between hepatic steatosis and atherogenic dyslipidemia after adjustment for obesity, physical activity, hyperglycemia, and systemic inflammation. We studied 6,333 asymptomatic subjects without clinical cardiovascular disease undergoing a health screen in Brazil from November 2008 to July 2010. Hepatic steatosis was diagnosed by ultrasound. Atherogenic dyslipidemia was defined using 2 definitions: criteria for (1) metabolic syndrome or (2) insulin resistance (triglyceride/high-density-lipoprotein cholesterol ratio of ≥2.5 in women and ≥3.5 in men). In hierarchical multivariate regression models, we evaluated for an independent association of hepatic steatosis with atherogenic dyslipidemia. Hepatic steatosis was detected in 36% of participants (average age 43.5 years, 79% men, average body mass index 26.3 kg/m(2)). Subjects with hepatic steatosis had similar levels of low-density-lipoprotein cholesterol, with significantly lower level of high-density-lipoprotein cholesterol and higher level of triglyceride compared with those without steatosis. Hepatic steatosis remained significantly independently associated with atherogenic dyslipidemia of both definitions (metabolic syndrome [odds ratio 2.47, 95% confidence interval 2.03 to 3.02] and insulin resistance [odds ratio 2.50, 95% confidence interval 2.13 to 2.91]) after multivariate adjustment. Stratified analyses showed a persistent independent association in nonobese subjects, those without metabolic syndrome, those with normal high-sensitivity C-reactive protein, nonalcohol abusers, and those with normal liver enzymes. Hepatic steatosis was significantly associated with atherogenic dyslipidemia independent of obesity, physical activity, hyperglycemia, and systemic inflammation after multivariate adjustment. In conclusion, this adds to the growing body of evidence that hepatic steatosis may play a direct metabolic role in conferring increased cardiovascular risk.

Impact of lung transplantation on serum lipids in COPD

BACKGROUND

Severe chronic obstructive pulmonary disease is associated with high HDL cholesterol (HDL-C). We sought to examine the effect of lung transplantation on lipid profiles in patients with COPD.

METHODS

We analyzed 101 lung transplant recipients in a retrospective cohort of patients from two centers in whom lipid values were available both before as well as after transplantation. Sixty-one subjects were transplanted for severe COPD (93% GOLD stage 4).

RESULTS

Eighty-nine percent of subjects with COPD exhibited a decline in HDL-C. Median decline for the COPD cohort was 25 mg/dL (IQR 12-38 mg/dL, p < 0.0001). Non-COPD subjects exhibited no significant changes in HDL-C. Other lipid changes in the COPD cohort included a rise in triglycerides of 70 mg/dL (IQR 35 to 140, p < 0.0001). Decreases in HDL-C levels were independent from the rise in triglyceride levels. Neither LDL-C nor non-HDL-C demonstrated significant changes. Subjects with greater increases in prednisone exposure post-transplant exhibited lesser declines in HDL-C. Compared with tacrolimus, cyclosporine had no effect on observed changes in HDL-C or triglycerides, but was associated with a greater median rise in LDL-C.

CONCLUSIONS

In patients with COPD, lung transplantation results in reductions in the serum levels of HDL-C. These changes are not observed in patients undergoing lung transplantation for diagnoses other than COPD.

Statin therapy is associated with decreased pulmonary vascular pressures in severe COPD

BACKGROUND

Pulmonary hypertension (PH) in COPD carries a poor prognosis. Statin therapy has been associated with numerous beneficial clinical effects in COPD, including a possible improvement in PH. We examined the association between statin use and pulmonary hemodynamics in a well-characterized cohort of patients undergoing evaluation for lung transplantation.

METHODS

We conducted a cross-sectional analysis of 112 subjects evaluated for lung transplant with a diagnosis of COPD. Clinical characteristics, pulmonary function, cardiac catheterization findings and medical comorbidities were compared between statins users and non-users.

RESULTS

Thirty-four (30%) subjects were receiving statin therapy. Statin users were older and had an increased prevalence of systemic hypertension and coronary artery disease (CAD). Mean pulmonary arterial pressure (mPAP) in the statin group was lower [26 ± 7 vs 29 ± 7 mmHg, p = 0.02], as was pulmonary artery wedge pressure (PAWP) [12 ± 5 vs. 15 ± 6 mmHg, p = 0.02]. Pulmonary vascular resistance did not differ between the groups. In multiple regression analysis, statin use was associated with a 4.2 mmHg (95% CI: 2 to 6.4, p = <0.001) lower PAWP and a 2.6 mmHg (95% CI: 0.3 to 4.9, p = 0.03) reduction in mPAP independent of PAWP.

CONCLUSIONS

In patients with severe COPD, statin use is associated with significantly lower PAWP and mPAP. These finding should be evaluated prospectively.

Assessment of gender-specific preventive cardiovascular knowledge among house staff: Potential impact on cardiovascular management

BACKGROUND

Gender differences in cardiovascular prevention and treatment may be related to physicians' level of postgraduate training and gender.

OBJECTIVES

This study was designed to assess resident physician knowledge concerning general and gender-specific preventive cardiology topics and to determine whether there were differences in that knowledge based on the physicians' level of postgraduate training or gender.

METHODS

A 29-item true/false questionnaire was administered to residents in a large, university-based internal medicine residency program. All questions were drawn from evidence-based practice guidelines, and a subset of questions pertained to gender-specific issues in cardiovascular disease prevention. Scores on the overall test and gender-specific subset were computed as a percentage of correct answers. Differences were compared by postgraduate year (PGY) of training and physician gender.

RESULTS

Of the 190 eligible residents, 159 (88 men, 67 women, 4 not specified) completed the questionnaire. Overall test scores differed significantly by PGY (PGY-1, 83.4% correct answers; PGY-2, 52.9%; PGY-3, 65.3%; P < 0.001 for each paired comparison), but did not differ significantly by physician gender (males, 73.5%; females, 70.0%). Performance on gender-specific items also differed by PGY (PGY-1, 72.2% vs PGY-2, 20.0%; P < 0.001; and PGY-1, 72.2% vs PGY-3, 45.1%; P < 0.001). Knowledge of gender-specific preventive cardiology did not differ significantly by physician gender (males, 56.4%; females, 49.0%).

CONCLUSIONS

Residents in PGY-1 had better knowledge of preventive cardiology as assessed using this questionnaire than did residents in PGY-2 or PGY-3. Knowledge of general and gender-specific cardiology topics was not related to physician gender.