Pulmonary function in patients with acute coronary syndrome treated with ticagrelor or clopidogrel (from the Platelet Inhibition and Patient Outcomes [PLATO] pulmonary function substudy)

The Platelet Inhibition and Patient Outcomes (PLATO) trial showed that ticagrelor reduced the risk for cardiovascular events in patients with acute coronary syndromes compared to clopidogrel but was associated with increased incidence of dyspnea. This substudy assessed whether ticagrelor affects pulmonary function in patients with acute coronary syndromes: 199 patients enrolled in the PLATO trial and receiving randomized treatment with ticagrelor 90 mg twice daily (n = 101) or clopidogrel 75 mg/day (n = 98) took part in the pulmonary function substudy. Patients with advanced lung disease, congestive heart failure, or coronary artery bypass graft surgery after the index event were excluded. Pulse oximetry (blood oxygen saturation), spirometry (forced expiratory volume in 1 second, forced vital capacity, and forced expiratory flow between 25% and 75% of forced vital capacity before and 20 minutes after inhalation of a β(2) agonist), lung volumes (total lung capacity, functional residual capacity, residual volume), and diffusion capacity were performed after patients received study medication for 30 to 40 days. Tests were then repeated <10 days before and approximately 30 days after the discontinuation of study medication. After a mean treatment duration of 31 days, there were no differences between the groups for any of the pulmonary function parameters. At the end of treatment (mean 211 days) and after the discontinuation of study medication (mean 32 days after the last dose), there was also no evidence of a change in pulmonary function in either group. For example, forced expiratory volume in 1 second values before β(2) agonist inhalation in the ticagrelor and clopidogrel groups were 2.81 ± 0.73 and 2.70 ± 0.84 L, respectively, at the first visit and did not change significantly at subsequent visits. In conclusion, no effect of ticagrelor on pulmonary function was seen in this cohort of patients with acute coronary syndromes compared to clopidogrel.     

Impact of the history of congestive heart failure on the utility of B-type natriuretic peptide in the emergency diagnosis of heart failure: results from the Breathing Not Properly Multinational Study

Purpose

B-type natriuretic peptide is known to correlate with hemodynamic state, presence and severity of congestive heart failure, and prognosis. Although low-range B-type natriuretic peptide less than 100 pg/mL has a high negative predictive value (90%), and high-range B-type natriuretic peptide greater than 500 pg/mL has a high positive predictive value (87%), there remains some ambiguity in the interpretation of results in the medium range (100-500 pg/mL). We hypothesized that taking into account the history of congestive heart failure along with other clinical variables would be helpful in this range of B-type natriuretic peptide levels.

Method

The Breathing Not Properly Multicenter Study was an international, 7-center, prospective study including 1475 patients with a mean age of 63 years (57% were male, and 54% were female); 35% of patients with a history of congestive heart failure were enrolled, and a final diagnosis of congestive heart failure was made in 46%. The index criteria was defined as positive if any 2 index findings (ie, history of coronary artery disease, lower extremity edema, pulmonary edema, cephalization of the pulmonary arteries, and cardiomegaly) were present.

Results

The interval likelihood ratios (LR) for low, medium, and high B-type natriuretic peptide ranges are 0.13, 1.85, and 8.1, respectively. For medium B-type natriuretic peptide levels a positive history of congestive heart failure makes the diagnosis of congestive heart failure more probable with a cumulative LR of 4.3. Also in this range a positive index criterion was strongly indicative of congestive heart failure even in the absence of a history of congestive heart failure (LR 3.3). Where there are both a positive history of congestive heart failure and a positive index criteria for the medium B-type natriuretic peptide group, the cumulative LR (10.2) is similar to that of a high B-type natriuretic peptide level (8.1).

Conclusion

Even in the medium range (100-500 pg/mL), when using the history of congestive heart failure and index criteria, B-type natriuretic peptide can be a powerful diagnostic tool in the hands of clinicians in the emergency department.     

Predischarge C-reactive protein and 1-year outcome after acute coronary syndromes

Purpose

To investigate the relationship between high-sensitivity C-reactive protein and cardiovascular events following acute coronary syndrome.

Methods

This nationwide, cross-sectional, prospective study involved 439 patients with an acute coronary syndrome who presented to the hospital within 24 hours of symptom onset. Patients with a concomitant inflammatory process were excluded. Predischarge C-reactive protein samples were measured using a high-sensitivity method in a core laboratory. The outcome was the composite of death, acute myocardial infarction, stroke/transient ischemic attack, urgent hospitalization for unstable angina, and urgent revascularization within 1 year.

Results

At 1 year, event rates were 10.2% for the lowest, 8.2% for the middle, and 11.0% for the highest C-reactive protein tertiles (P = .75) with similar event-free survival (P = .70). The hazard ratio (HR) for event rates between the highest and lowest tertiles was 1.10 (95% confidence interval [CI]: 0.54 to 2.20) There was marked overlap of C-reactive protein values between patients with and without events (median [interquartile range]: 8.39 [3.27 to 32.63] vs 9.55 [4.07 to 24.02], respectively; P = .91). C-reactive protein was not an independent predictor of 1-year events (HR for highest tertile: 1.19; 95% CI: 0.58 to 2.43; P = .64) and performed poorly on receiver operating characteristic curve analysis (C statistic = 0.51).

Conclusion

Predischarge high-sensitivity C-reactive protein level is a poor predictor of cardiovascular events at 1 year after acute coronary syndrome.