2387Recurrent cardiovascular events and mortality in relation to antiplatelet therapy in patients with myocardial infarction without obstructive coronary artery disease (MINOCA)

Background

Approximately 10% of patients presenting with myocardial infarction (MI) do not have obstructive coronary artery disease (MINOCA). The role of antiplatelet therapy and outcomes in this group remain unclear. We assessed prognosis and the effect of an intensified clopidogrel regimen in MINOCA patients.

Methods

We analyzed data from the CURRENT-OASIS 7 trial, which randomized 25,086 patients with acute coronary syndromes (ACS) referred for early intervention to receive either double-dose (600mg day 1; 150mg days 2–7; then 75mg daily) or standard-dose (300mg day 1; then 75mg daily) clopidogrel. We evaluated clinical outcomes at 30-days in patients with versus without obstructive CAD and in relation to standard versus double-dose clopidogrel.

Results

Overall, 23,783 MI patients were included, of which 1,599 (6.7%) had MINOCA. MINOCA patients were younger, more frequently presented with non-ST-segment elevation MI and had fewer comorbidities. Rates of all-cause mortality (0.7% versus 2.4%, p=0.0046), cardiovascular mortality (0.6 versus 2.2%, p=0.0056), repeat MI (0.5% versus 2.3%, p=0.0009) and major bleedings (0.7% versus 2.5%, p=0.0001) were significantly lower among patients with MINOCA versus those with obstructive CAD. Compared with the standard-dose clopidogrel regimen, the double-dose regimen appeared to increase the risk of cardiovascular death, MI or stroke in MINOCA patients (0.8% versus 2.1%, hazard ratio (HR) 2.74, P=0.033). There was no difference in those with obstructive CAD (4.7% versus 4.4%, HR 0.93, P=0.226; P-for-interaction=0.023) (see Figure 1A). Major bleeding did not occur more frequently in MINOCA patients with double- versus standard-dose clopidogrel regimen (0.7% versus 0.6%, (HR 1.16 (95% CI 0.35–3.80), p=0.805), but their rate was higher In MI patients with obstructive CAD (2.7% versus 2.2% (HR 1.26 (95% CI 1.06–1.49), p=0.008) (Figure 1B).

Figure 1A & B

Conclusions

Compared to MI patients with obstructive CAD, patients presenting with MINOCA represent a distinct cohort, which is generally younger, has a higher NSTEMI prevalence and fewer comorbidities. Their risk for adverse events, especially repeat MI, stroke, death, and bleeding, is low (<1%) at 30 days. Applying an intensified clopidogrel regimen in MINOCA patients appears to be related to a higher risk for CV death, MI and stroke. Accordingly, more potent antiplatelet regimens might be harmful among MINOCA patients and should not be administered routinely. Nevertheless, there is a need for more prospective studies evaluating the role of dual antiplatelet therapies in MINOCA patients.

Acknowledgement/Funding

The CURRENT-OASIS 7 trial was sponsored by Sanofi-Aventis and Bristol-Myers Squibb.

[The DISC tool improves communication and results in pulmonary rehabilitation]

INTRODUCTION

Competence in personal relationships is essential for a caregiver, especially in pulmonary rehabilitation (PR). Considering the behavioral profile of patients might help to optimize their management and the results of PR.

METHODS

We evaluated eight hundred and thirty-two consecutive patients with chronic respiratory disease who received eight weeks of home-based PR. Their exercise tolerance (six-minute stepper test, 6MST), mood (HAD), and quality of life (VSRQ, MRF28) were evaluated at the beginning and end of PR. For six hundred and ninety patients, a behavioral approach was implemented at the beginning of PR by using the DISC tool to identify four behavioral profiles: dominance, influence, steadiness, conscientiousness. The remaining 142 patients served as the control group.

RESULTS

Subjectively, the therapeutic alliance was more easily established with the behavioral approach. Compared with the control group, patients with the "steadiness" profile were younger (60.7±12 years) and mostly female (52.8%), whereas patients with the "conscientiousness" profile were older (67.5±10.6 years) and mostly male (85.5%). The four behaviorally profiled groups showed no differences in exercise tolerance, mood, or quality of life scores at baseline. Globally, all patients improved their exercise tolerance, mood and quality of life. The percentage of responders to 6MST and VSRQ (>MCID) was 7.5% and 5.3% higher with the behavioral approach. For non-responders to 6MST and VSRQ (<MCID), only patients benefiting from the behavioral approach improved the other parameters studied, patients from control group having exhibited no improvement at all.

CONCLUSIONS

The DISC-guided behavioral approach improves the patient-caregiver relationship and achieves better results at the end of PR.

Rationale and design of ACTIVE: the atrial fibrillation clopidogrel trial with irbesartan for prevention of vascular events

BACKGROUND

Atrial fibrillation (AF) is the most frequently occurring cardiac arrhythmia with often serious clinical consequences. Many patients have contraindications to anticoagulation, and it is often underused in clinical practice. The addition of clopidogrel to aspirin (ASA) has been shown to reduce vascular events in a number of high-risk populations. Irbesartan is an angiotensin receptor-blocking agent that reduces blood pressure and has other vascular protective effects.

METHODS AND RESULTS

ACTIVE W is a noninferiority trial of clopidogrel plus ASA versus oral anticoagulation in patients with AF and at least 1 risk factor for stroke. ACTIVE A is a double-blind, placebo-controlled trial of clopidogrel in patients with AF and with at least 1 risk factor for stroke who receive ASA because they have a contraindication for oral anticoagulation or because they are unwilling to take an oral anticoagulant. ACTIVE I is a partial factorial, double-blind, placebo-controlled trial of irbesartan in patients participating in ACTIVE A or ACTIVE W. The primary outcomes of these studies are composites of vascular events. A total of 14000 patients will be enrolled in these trials.

CONCLUSIONS

ACTIVE is the largest trial yet conducted in AF. Its results will lead to a new understanding of the role of combined antiplatelet therapy and the role of blood pressure lowering with an angiotensin II receptor blocker in patients with AF.

High-dose mitoxantrone and cyclophosphamide without stem cell support in high-risk and advanced solid tumors: a phase I trial

This phase I study was designed to develop a high-dose combination of two cycles of mitoxantrone and cyclophosphamide in patients with solid tumors, as an alternative to single-cycle high-dose regimens that use only alkylating agents. Treatment was delivered with granulocyte colony-stimulating factor (G-CSF), but without stem cell support, in order to avoid potential tumor cell reinfusion. Thirty-one patients with advanced solid tumors received two cycles of high-dose mitoxantrone (20-30 mg/m2) plus high-dose cyclophosphamide (3000-4000 mg/m2). All patients received G-CSF until hematologic recovery. Dose-escalation was performed when less than 50% of cycles per level had dose-limiting toxicity (DLT). The maximum tolerated dose (MTD) achieved was mitoxantrone 25 mg/m2 and cyclophosphamide 4000 mg/m2. Main dose-limiting toxicities (DLTs) were hematological: grade IV neutropenia lasting more than 7 days and thrombopenia below 20 x 10(9)/l requiring more than one platelet transfusion. Non-hematological DLT consisted predominantly of grade III emesis and asthenia. Follow-up after each cycle was performed in an outpatient setting and there were no toxic deaths. In conclusion, the administration of two cycles of high-dose mitoxantrone and cyclophosphamide with G-CSF support is safe and feasible. MTD was mitoxantrone 25 mg/m2 and cyclophosphamide 4000 mg/m2. Evaluation of this regimen is being done in a phase II trial.

Effects of atrial impulse timing on AV concealed conduction in the rabbit heart

The influence of the timing of a nontransmitted or transmitted atrial impulse on the atrioventricular (AV) conduction time of the subsequent impulse was studied in nine isolated rabbit hearts. AV conduction curves were determined by applying the atrial extrastimulus test. The extrastimulus was delivered preceded or not by an interposed atrial impulse whose coupling interval with respect to the last atrial beat of a basic train was kept constant at 100, 120, 140, 160, 175, 200, 225, 250, and 300 msec. In all experiments, there was a "concealment interval," i.e., the AV effective refractory period was longer than the atrial functional refractory period, and in seven experiments was comprised between 100 and 160 msec. For any given extrastimulus coupling interval in the presence of an interposed nontransmitted atrial impulse, AV conduction time was significantly greater than in its absence; the increase was greater than the longer the nontransmitted atrial impulse coupling interval, i.e., the shorter the subsequent transmitted impulse coupling interval with respect to the previous interposed nontransmitted impulse. The AV conduction curves relating the extrastimulus AV conduction time to its coupling interval with respect to the last atrial impulse of the basic train fitted to a hyperbolic model both in the absence of the interposed atrial impulse and in its presence (mean square residual 31 +/- 23 msec2), and the interposed atrial impulse modified the constants of the functions; the slope of the linear transformations was progressively more negative as the interposed atrial impulse was delayed. Furthermore, the effects of the interposed atrial impulse--transmitted or not--on AV conduction time of the subsequent impulse were qualitatively similar, their magnitude depending on the time elapsed were qualitatively similar, their magnitude depending on the time elapsed between the two.

Closed chest radiofrequency ablation of the sinoatrial node in dogs

Transcatheter ablation of the sinoatrial node with radiofrequency energy (0.6 MHZ, 2.5-5 watts) was performed in 10 dogs under fluoroscopic monitoring and autonomic blockade. Sinus function was previously studied in terms of cycle length, recovery time and atrial activation pattern by catheter mapping. Several discharges (8-22) were applied for variable periods of time (maximum 1 minute). Sinus tachycardia and/or sinus arrest during ablation confirmed correct catheter position. Sinus rhythm was abolished in eight dogs. The ectopic rhythm was atrial in six and AV nodal in two dogs. Ectopic atrial cycle length and recovery time were longer than the baseline sinus values: 724 +/- 321 versus 509 +/- 147, P less than 0.05; 1103 +/- 775 versus 618 +/- 151, P less than 0.05 (values in msec). The study was repeated 10-14 days later in six dogs; three maintained the same atrial rhythm, one persisted in sinus rhythm, and one dog changed from atrial to sinus rhythm, whereas another changed from sinus to atrial rhythm. Gross findings revealed transmural lesions in all dogs, without perforation. Histology in chronic dogs showed sinus cell necrosis and its replacement by granulation tissue.

IN CONCLUSION

sinus function may be abolished by closed chest radiofrequency ablation.

Clinical use of the arterial/alveolar oxygen tension ratio

A prospective study to verify the behavior of the arterial/alveolar oxygen tension ratio (PaO2/PAO2) at different fractions of inspired oxygen (FIO2), was performed in 15 adult hypoxemic patients. This index was useful not only for predicting the arterial oxygen tension but also for choosing the necessary oxygen supplementary levels. PaO2/PAO2 was a less reliable index in patients with mild intrapulmonary shunts, probably because of changes in the distribution of alveolar ventilation/perfusion ratios.