Increased use of azithromycin (AZ) in treating infections associated with coronavirus disease 2019 (COVID‐19) and reports of increased incidence of prolonged corrected QT (QTc) interval associated ...with AZ used with hydroxychloroquine prompted us to review the latest evidence in the literature, present additional analyses of human cardiovascular (CV) electrophysiology studies, and to describe sequential steps in research and development that were undertaken to characterize the benefit‐risk profile of AZ. Combined QTc findings from electrocardiograms taken during oral and i.v. pharmacokinetic‐pharmacodynamic studies of AZ suggest that clinically meaningful QTc prolongation is unlikely. Findings from several observational studies were heterogeneous and not as consistent as results from at least two large randomized controlled trials (RCTs). The QTc findings presented and observational data from studies with large numbers of events are not consistent with either a proarrhythmic action of AZ or an increase in frequency of CV deaths. Well‐powered RCTs do not suggest a presence of increased risk of CV or sudden cardiac death after short‐term or protracted periods of AZ usage, even in patients at higher risk from pre‐existing coronary disease.
Inhibition of the acyl coenzyme A:cholesterol acyltransferase (ACAT) enzyme may prevent excess accumulation of cholesteryl esters in macrophages. The ACAT inhibitor avasimibe was shown to reduce ...experimental atherosclerosis. This study was designed to investigate the effects of avasimibe on human coronary atherosclerosis.
This randomized, double-blind, placebo-controlled trial assessed the effects of avasimibe at dosages of 50, 250, and 750 mg QD on the progression of coronary atherosclerosis as assessed by intravascular ultrasound (IVUS). All patients received background lipid-lowering therapy if necessary to reach a target baseline LDL level <125 mg/dL (3.2 mmol/L). IVUS and coronary angiography were performed at baseline and repeated after up to 24 months of treatment. Approximately equal percentages of patients across groups received concurrent statin therapy (87% to 89%). The mean total plaque volume at baseline was approximately 200 mm3, and the least squares mean change at end of treatment was 0.7 mm3 for placebo and 7.7, 4.1, and 4.8 mm3 for the avasimibe 50, 250, and 750 mg groups, respectively (adjusted P=0.17 unadjusted P=0.057, 0.37, and 0.37, respectively). Percent atheroma volume increased by 0.4% with placebo and by 0.7%, 0.8%, and 1.0% in the respective avasimibe groups (P=NS). LDL cholesterol increased during the study by 1.7% with placebo but by 7.8%, 9.1%, and 10.9% in the respective avasimibe groups (P<0.05 in all groups).
Avasimibe did not favorably alter coronary atherosclerosis as assessed by IVUS. This ACAT inhibitor also caused a mild increase in LDL cholesterol.
Background:
The ICH E9(R1) addendum states that the strategy to account for intercurrent events should be included when defining an estimand, the treatment effect to be estimated based on the study ...objective. The estimator used to assess the treatment effect needs to be aligned with the estimand that accounted for intercurrent events. Regardless of the strategy, missing data resulting from patient premature withdrawal could undermine the robustness of the study results. Informative censoring due to dropouts in an events-based study is one such example. Sensitivity analyses using imputation methods are useful to examine the uncertainty due to informative censoring and address the robustness and strength of the study results.
Methods:
We assessed the effect of premature patient withdrawal in the PRECISION study, a randomized non-inferiority clinical trial of patients with chronic arthritic pain that compared the cardiovascular safety of three nonsteroidal anti-inflammatory drugs–based treatment policies or paradigms. The protocol-defined use of concomitant or rescue medications was permitted since changes in pain medications due to insufficient analgesia were expected in patients in this long-term study. Anticipating that premature study discontinuations could potentially lead to informative censoring, a supplementary analysis was pre-specified in which censored outcomes due to the premature study discontinuation were imputed based on adverse events that were clinically associated with the primary endpoint (cardiovascular outcome based on the Antiplatelet Trialists Collaboration composite endpoint). Furthermore, tipping point analyses were conducted to test the robustness of the primary analysis results by assuming data censored not at random. The level of increase at which the primary study conclusion would change was estimated.
Results:
For the analysis of time to first primary endpoint event through 30 months, 4065 out of the 24,081 enrolled patients were lost to follow-up, withdrew consent, or were no longer willing to participate in the study. These withdrawals occurred gradually and resulted in a cumulative total of 5893 censored patient-years of observation (10.2%). The rate of discontinuation and the baseline characteristics of the discontinued patients were similar across the three treatment groups. The non-inferiority conclusion from the primary analysis was confirmed in the supplementary analysis incorporating relevant adverse events. Furthermore, tipping point analyses demonstrated that in order to lose non-inferiority in the primary analysis, the risk of primary endpoint events during the censored observation time would have to increase by more than 2.7-fold in the celecoxib group while remaining constant in the other nonsteroidal anti-inflammatory drugs groups, demonstrating that the scenarios where the study results are invalid appear not plausible.
Conclusions:
Supplementary and sensitivity analyses presented to address informative censoring in PRECISION helped to further interpret and strengthen the study results.
Background In patients with chronic heart failure (CHF), diuretic requirements increase as the disease progresses. Because diuretic resistance can be overcome with escalating doses, the evaluation of ...CHF severity and prognosis may be incomplete without considering the intensity of therapy. Methods The prognostic importance of diuretic resistance (as evidenced by a high-dose requirement) was retrospectively evaluated in 1153 patients with advanced CHF who were enrolled in the Prospective Randomized Amlodipine Survival Evaluation (PRAISE). The relation of loop diuretic and angiotensin-converting enzyme inhibitor doses (defined by their median values) and other baseline characteristics to total and cause-specific mortality was determined by proportion hazards regression. Results High diuretic doses were independently associated with mortality, sudden death, and pump failure death (adjusted hazard ratios HRs 1.37 P =.004, 1.39 P =.042, and 1.51 P =.034, respectively). Use of metolazone was an independent predictor of total mortality (adjusted HR = 1.37, P =.016) but not of cause-specific mortality. Low angiotensin-converting enzyme inhibitor dose was an independent predictor of pump failure death (adjusted HR = 2.21, P =.0005). Unadjusted mortality risks of congestion and its treatment were additive and comparable to those of established risk factors. Conclusions The independent association of high diuretic doses with mortality suggests that diuretic resistance should be considered an indicator of prognosis in patients with chronic CHF. These retrospective observations do not establish harm or rule out a long-term benefit of diuretics in CHF, because selection bias may entirely explain the relation of prescribed therapy to death. (Am Heart J 2002;144:31-8.)
Objectives To determine the efficacy and safety of eplerenone therapy in children with hypertension. Study design A total of 304 children age 4-16 years with systolic blood pressure (SBP) ≥95th ...percentile were randomized to low-dose (25 mg daily), middle-dose (25 mg twice daily), or high-dose (50 mg twice daily) eplerenone (phase A), then rerandomized to active therapy or placebo for another 4 weeks (phase B). The primary endpoint was change in SBP in phase B. Results During phase A, mean SBP decreased from baseline by 8 mm Hg, and diastolic blood pressure (DBP) decreased by up to 3.8 mm Hg; no dose-response relationship was demonstrated. Mean differences in SBP from placebo during phase B were -2.61 for the low-dose group, +2.32 for the middle-dose group, and -2.76 mm Hg for the high-dose group; only the reduction in the high-dose group was statistically significant ( P = .048). No significant effects on DBP of eplerenone therapy relative to placebo were detected. Eplerenone was well tolerated, with a rate of adverse events comparable to that of placebo. Conclusions Short-term treatment with eplerenone reduced blood pressure in children with hypertension and had acceptable tolerability.
We assessed the effects of radiofrequency catheter ablation (RFCA) of the atrial epicardium on pacing-induced sustained atrial fibrillation (AF) and the expression and distribution of the ...intercellular gap junction protein connexin 43 (Cx43) in dogs.
In 12 mongrel dogs, after creation of complete AV block and implantation of a ventricular inhibited pacemaker, a high-rate pulse generator (20 to 30 Hz to induce AF) was implanted in the neck, connected to a right atrial endocardial pacing lead, and used to pace the atrium for 10 to 14 weeks. In group 1 (n=9 dogs), corrected sinus node recovery time (CSNRT), P-wave duration, 24-hour Holter ECG, maximal heart rate (MHR) in response to isoproterenol, and intrinsic heart rate (IHR) after atropine (0.04 mg/kg) and propranolol were measured before and after atrial pacing and RFCA. Group 2 dogs were used to assess the effect of chronic AF alone on Cx43 expression and distribution. All group 1 dogs developed sustained (>24 hours) AF. Right-sided RFCA of the atria eliminated the sustained AF in 5 dogs, but both right and left atrial RFCA was required to abolish sustained AF in the other 4 dogs. After RFCA restored sinus rhythm, CSNRT and P-wave duration were prolonged and MHR and IHR were decreased. Chronic rapid atrial pacing (group 2) increased the expression of Cx43, which was absent in ablated areas and markedly depressed in viable atrial myocytes near the ablation zones (group 1).
Rapid atrial pacing for long time periods induced sustained AF that can be eliminated by linear right and left atrial lesions created with RFCA, with preservation of sinus rhythm and atrial contractile function. Chronic AF increased the expression and distribution of gap junction protein Cx43, which became reduced in ablated and nearby nonablated areas.
Inhibition of phosphodiesterase 5 is an attractive candidate mechanism for blood pressure (BP) lowering. In this study, a novel long-acting phosphodiesterase 5 inhibitor, PF-00489791, was evaluated ...in 133 patients with mild to moderate hypertension, randomized into 1 of 4 groups: placebo, 4 mg, 10 mg, and 20 mg titrated after 14 days of dosing to 40 mg. Study medication was administered once daily for 28 days. Ambulatory BP monitoring was used. There was a statistically significant decrease (compared with placebo) in mean daytime systolic BP on day 28 at the 10 and 20/40 mg doses (by approximately 5 and approximately 7 mm Hg, respectively). Changes in mean daytime diastolic BP corresponded with those in systolic BP. The magnitude of BP lowering was greater on day 1 than on days 14 and 28, but the response was sustained between days 14 and 28. PF-00489791 also exerted BP lowering effects on mean 24-hour ambulatory BP. There was a dose-related increase in plasma cGMP concentration (statistically significant at the 20/40 mg dose). There was an increased incidence of headaches at the 10 and 20/40 mg doses (22% and 21%, respectively, compared with 12% with placebo) and an increased incidence of dyspepsia/gastroesophageal reflux disease and musculoskeletal adverse events at the 20/40 mg dose. In conclusion, PF-00489791 causes a clinically meaningful and sustained BP lowering in patients with hypertension. It is generally safe and well tolerated at the clinically efficacious doses.
Objectives. We sought to determine whether the beneficial effects of amlodipine in heart failure may be mediated by a reduction in tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) ...levels. We postulated that TNF-alpha and IL-6 levels may also have predictive value in patients with congestive heart failure (CHF).
Background. The molecular mechanism for progression of CHF may involve cytokine overexpression. The effect of amlodipine on cytokine levels in patients with CHF is unknown.
Methods. In the Prospective Randomized Amlodipine Survival Evaluation (PRAISE) trial, we used enzyme-linked immunosorbent assay to measure plasma levels of TNF-alpha in 92 patients and IL-6 in 62 patients in New York Heart Association functional classes III and IV randomized to receive amlodipine (10 mg/day) or placebo. Blood samples were obtained for cytokine measurement at baseline and at 8 and 26 weeks after enrollment.
Results. The baseline amlodipine and placebo groups did not differ in demographics and cytokine levels. Mean (±SD) plasma levels of TNF-alpha were 5.69 ± 0.32 pg/ml, and those of IL-6 were 9.23 ± 1.26 pg/ml at baseline. These levels were elevated 6 and 10 times, respectively, compared with those of normal subjects (p < 0.001). Levels of TNF-alpha did not change significantly over the 26-week period (p = 0.69). However, IL-6 levels were significantly lower at 26 weeks in patients treated with amlodipine versus placebo (p = 0.007 by the Wilcoxon signed-rank test). An adverse event—CHF or death—occurred more commonly in patients with higher IL-6 levels.
Conclusions. Amlodipine lowers plasma IL-6 levels in patients with CHF. The beneficial effect of amlodipine in CHF may be due to a reduction of cytokines such as IL-6.
(J Am Coll Cardiol 1997;30:35–41)
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