The INVICTUS rheumatic heart disease research program: Rationale, design and baseline characteristics of a randomized trial of rivaroxaban compared to vitamin K antagonists in rheumatic valvular disease and atrial fibrillation

BACKGROUND

Rheumatic heart disease (RHD) is a neglected disease affecting 33 million people, mainly in low and middle income countries. Yet very few large trials or registries have been conducted in this population. The INVICTUS program of research in RHD consists of a randomized-controlled trial (RCT) of 4500 patients comparing rivaroxaban with vitamin K antagonists (VKA) in patients with RHD and atrial fibrillation (AF), a registry of 17,000 patients to document the contemporary clinical course of patients with RHD, including a focused sub-study on pregnant women with RHD within the registry. This paper describes the rationale, design, organization and baseline characteristics of the RCT and a summary of the design of the registry and its sub-study. Patients with RHD and AF are considered to be at high risk of embolic strokes, and oral anticoagulation with VKAs is recommended for stroke prevention. But the quality of anticoagulation with VKA is poor in developing countries. A drug which does not require monitoring, and which is safe and effective for preventing stroke in patients with valvular AF, would fulfill a major unmet need.

METHODS

The INVestIgation of rheumatiC AF Treatment Using VKAs, rivaroxaban or aspirin Studies (INVICTUS-VKA) trial is an international, multicentre, randomized, open-label, parallel group trial, testing whether rivaroxaban 20 mg given once daily is non-inferior (or superior) to VKA in patients with RHD, AF, and an elevated risk of stroke (mitral stenosis with valve area ≤2 cm2, left atrial spontaneous echo-contrast or thrombus, or a CHA2DS2VASc score ≥2). The primary efficacy outcome is a composite of stroke or systemic embolism and the primary safety outcome is the occurrence of major bleeding. The trial has enrolled 4565 patients from 138 sites in 23 countries from Africa, Asia and South America. The Registry plans to enroll an additional 17,000 patients with RHD and document their treatments, and their clinical course for at least 2 years. The pregnancy sub-study will document the clinical course of pregnant women with RHD.

CONCLUSION

INVICTUS is the largest program of clinical research focused on a neglected cardiovascular disease and will provide new information on the clinical course of patients with RHD, and approaches to anticoagulation in those with concomitant AF.

Efficacy and effectiveness of valsartan/amlodipine and valsartan/amlodipine/hydrochlorothiazide in hypertension: randomized controlled versus observational studies

OBJECTIVE

The aim of this post-hoc analysis was to compare the results from randomized controlled trials (RCTs) and real-world evidence (RWE) studies of valsartan/amlodipine (Val/Aml) and valsartan/amlodipine/hydrochlorothiazide (Val/Aml/HCTZ) in patients with uncontrolled hypertension (>140/90 mmHg).

METHODS

Data was pooled from 15 RCTs (N = 5542) and 8 RWE studies (N = 1397) for Val/Aml; and 2 RCTs (N = 804) and 5 RWE studies (N = 9380) for Val/Aml/HCTZ. Patients who received Val/Aml (80/5, 160/5, 160/10, 320/5, or 320/10 mg), Val/Aml/HCTZ (160/5/12.5, 160/5/25, 160/10/12.5, 160/10/25, or 320/10/25 mg) or placebo were considered for this analysis. Only patients with both baseline and follow-up assessment within 60-90 days after baseline had been included in the analysis. Patients with missing values were excluded from the analysis. Using fitted linear mixed-effects model and random factors, treatment interactions and study design with mean sitting systolic blood pressure (msSBP), diastolic BP (msDBP) and pulse pressure (msPP) reductions from baseline to Week 8-12 of treatment were compared.

RESULTS

Baseline demographics and patient characteristics were comparable between RCT and RWE datasets and within Val/Aml and Val/Aml/HCTZ treatment groups. In both RCT and RWE studies, least-squares mean (LSM) reduction in msSBP/msDBP and msPP from baseline were significant (p < .05) across all dosages. The efficacy of Val/Aml in RCTs was statistically significantly greater than in RWE studies for msSBP/msDBP (-23.1/-13.8 vs. -17.9/-9.1 mmHg) but the difference was non-significant for msPP (-8.6 vs. -9.3 mmHg; p = .77). For Val/Aml/HCTZ, no direct comparison was available but a similar trend was observed. The difference observed for msSBP and msDBP may be due to routine practice setting, larger populations may have more confounders and different behaviors towards treatment adherence.

CONCLUSION

These findings demonstrate that the efficacy of Val/Aml and Val/Aml/HCTZ in RCTs was more pronounced compared with their effectiveness in RWE studies in different ethnic populations although the overall benefit was not different.

[Mutation and clinical relevance in a large cohort of unrelated Chinese patients with hypertrophic cardiomyopathy]

OBJECTIVE

To explore the genetic basis and phenotypic correlation with disease severity in a large cohort of Chinese patients with hypertrophic cardiomyopathy (HCM).

METHODS

A total of 179 unrelated Chinese HCM patients admitted to our department from 2002 to 2011 were enrolled in this study. Direct gene sequencing of β-myosin heavy chain (MYH7), myosin binding protein-C ( MYBPC3), and cardiac troponin T (TNNT2) were performed and clinical data were obtained in these patients.

RESULTS

A total of 34 mutations were identified in 40 patients (22.3%), 79.4% (27/34) mutations occurred only once and a possible hot spot, A26 in MYH7, was found. Distribution of mutations was 52.9% (18/34) (MYBPC3), 35.3% (12/34) ( MYH7) and 11.8% (4/34) (TNNT2) respectively. Double mutations were identified in 2.2% (4/179) patients. Genotype-positive patients were associated with an earlier symptom onset, severer left ventricular hypertrophy, a higher incidence of syncope, and were more likely to have positive family history of HCM or sudden cardiac death (SCD) , and were more likely to progress into heart failure (24.2% vs. 5.0%, P = 0.002) and at a higher risk of SCD (9.1% vs. 0, P = 0.009) during the 6.5-year follow-up. No statistical difference in any clinical parameters and outcomes was found between patients carrying MYBPC3 and MYH7 mutations. Double mutations were associated with malignant clinical progression in this cohort. Different phenotype severity could be seen in HCM patients with same genotype (e. g. MYH7-1736T, TNNT2-R92W).

CONCLUSION

MYBPC3 is the most predominant gene mutation in this HCM cohort. The presence of a sarcomere mutation in patients with HCM is associated with poor clinical outcome, although no specific genes or mutations can exactly predict the severity of clinical phenotypes.

Dobutamine infusion for unmasking long QT syndrome and torsades de pointes

Prolonged QT interval is usually seen on routine electrocardiogram (ECG), but in some patients it may only be seen immediately before the evolution of torsades de pointes (Tdp). To unmask the potential risk of Tdp in a patient with normal or borderline prolongation of QTc interval and recurrent syncope, dobutamine was given intravenously at a rate of 20 microg/kg/min. Strikingly, QTc prolongation was induced along with syncope after dobutamine infusion. Torsades de pointes occurred 5 d later when the patient received an implantable cardioverter defibrillator (ICD). Genetic testing revealed a mutation of the KNCQ(1)-gene encoding serine instead of glycine. The patient was treated with 75 mg of metoprolol twice daily, and at 12 mo follow-up he had no syncope or chest tightness. The ICD revealed no ventricular tachyarrhythmias or therapy delivered.

Association of genetic polymorphisms in the fibrinogen and platelet glycoprotein genes with unstable angina in Chinese patients

BACKGROUND

Inherited predisposition has been associated with coronary artery disease (CAD) in the white population.

HYPOTHESIS

The objective of this study was to investigate the association between the risk of unstable angina (UA) and genetic factors believed to be associated with an increased tendency toward thrombosis (the variable number of tandem repeats [VNTR] polymorphism of the platelet glycoprotein [GP] Ib alpha gene, Pl(A1/A2) of the platelet GP IIIa gene, 448G/A of the Bbeta fibrinogen gene and Thr312Ala of the Aalpha fibrinogen gene) in Chinese patients with UA.

METHODS

We performed a case/control study evaluating 69 Chinese patients (43 men, 26 women) with UA and 69 control subjects without CAD, individually matched for age and gender. The restriction fragment length polymorphism (RFLP) method was used to determine the genetic polymorphisms.

RESULTS

The frequencies of GP Ib alpha C/B genotype and Bbeta fibrinogen 448A allele were higher in patients with UA (46.4 vs. 30.4%, odds ratio [OR] 1.977, 95% confidence interval [CI] 0.98-3.97, p = 0.054, and 49.3 vs. 20.3%, OR 3.816, 95% CI 1.797-8.103, p = 0.000, respectively). Only four subjects (two cases, two controls) with GP IIIa Pl(A2) allele were found, and there was no association between Aalpha fibrinogen Thr312Ala polymorphism and UA.

CONCLUSIONS

Chinese patients with UA had increased frequencies of GP Ib alpha C/B genotype and Bbeta fibrinogen 448A allele. These data suggest that some genetic factors may influence the development of UA.

Persistence of the antihypertensive efficacy of amlodipine and nifedipine GITS after two 'missed doses': a randomised, double-blind comparative trial in Asian patients

Suboptimal management of hypertension is often a result of poor patient compliance in the form of missed doses of their antihypertensive medication. This multicentre, randomised, double-blind, parallel-group trial was designed to compare the persistence of the antihypertensive efficacy of the amlodipine and nifedipine gastrointestinal therapeutic system (GITS) after two 'missed doses', and also to compare the drugs' overall efficacy and safety in Asian patients with mild-to-moderate essential hypertension. Following a 2-week placebo run-in period, 222 patients were randomised to receive either amlodipine (5 mg daily, increased after 6 weeks if necessary to 10 mg daily, n=109) or nifedipine GITS (30 mg daily, increased after 6 weeks if necessary to 60 mg daily; n=113) for 12 weeks. A placebo was then substituted for further 2 days with continuous ambulatory blood pressure (BP) monitoring. The increases in the last 9 h of mean ambulatory BP on day 2 after treatment withdrawal were significantly less with amlodipine than with nifedipine GITS: 4.4+/-7.0 vs 11.2+/-11.3 mmHg for systolic BP (P<or=0.0001) and 2.4+/-6.3 vs 6.0+/-6.0 mmHg for diastolic BP (P<or=0.0002). Significant differences between the two drugs in mean 24-h ambulatory BP levels were already evident on day 1 after withdrawal, even though there were no significant differences on the final day of treatment. No differences in safety parameters were observed, and neither drug caused any serious or severe treatment-related adverse events. In conclusion, amlodipine provides greater protection than nifedipine GITS against loss of BP control following missed doses.

Evaluation of the patency rate of infarct-related artery after intravenous urokinase in acute myocardial infarction by 90 minutes angiography. Collaborative Group of Clinical Trial for Urokinase Therapy

OBJECTIVE

To evaluate the efficacy of intravenous (i.v.) thrombolytic therapy on acute myocardial infarction (AMI) and to evaluate the sensitivity and specificity of clinical criteria in deciding reperfusion rate by using 90 minutes angiography after initiation of the i.v. urokinase (UK).

METHODS

Coronary artery angiography (CAG) was performed in 124 out of 1406 patients with AMI receiving i.v. UK (UKTP) (Guangdong Techpool Biochemical Pharmaceutical Co. Ltd. Guangzhou, China) from November 1994 to April 1996. 1.5 million units of UKTP were infused in 111 patients, 2.0 million units in 10 patients and 1.0 million in 3 cases within 30 minutes. CAG was performed 90 minutes after the initiation of thrombolytic therapy.

RESULTS

Fifty-two patients had coronary flow grade of TI-MI-3 and 38 patients TIMI-2 90 minutes after the onset of thrombolytic therapy. The total patency rate of infarct related artery (IRA) was 72.6%. There was no significant difference (P > 0.05) in the patency rate of IRA of various locations. The patency rate of LAD was 71.6% (53/74), of RCA was 71.4% (30/42), of LCX was 85.7% (6/7) and effective patency in one patient with left main artery occlusion. Although there was a tendency that the earlier the thrombolytic therapy, the higher the patency rate of IRA patency, the results did not meet the statistically significant level (P > 0.05). Using CAG as the gold standard, the clinical criteria used for evaluation of reperfusion rate had a sensitivity of 88%, specificity of 69% and accuracy of 83% in prediction of the reperfusion of IRA.

CONCLUSION

UK is effective and reliable in i.v. thrombolytic therapy of AMI. The clinical criteria used to predict reperfusion of IRA have a higher sensitivity and relatively lower specificity.