Isosorbide dinitrate inhibits platelet adhesion and aggregation in nonthrombolyzed patients with acute myocardial infarction

Higher than recommend dosage of sublingual isosorbide dinitrate for treating angina pectoris: a case report and review of the literature

Nitrates primarily cause arterial and venous vasodilation effects, which increases coronary artery blood supply, and decreases cardiac preload and afterload by enhancing nitric oxide (NO) levels. The dosage of nitrates used for angina pectoris widely differs among individuals, and therapeutic resistance and tolerance gradually occur. Increasing doses of nitrates are needed to abolish ischemia chest pain onset in patients with angina pectoris, and to obtain satisfactory therapeutic effects. Here, we report the case of a 37-year-old male who was hospitalized six times, from September 2013 to April 2018, with recurrent angina pectoris. Although the patient was implanted with stents, he still presented with chest pain associated with physical efforts. Diagnosis with acute myocardial infarction was based on his ST-segment changes on electrocardiogram (ECG), elevated troponin-T level and coronary angiography. After the stents were implanted, his chest pain had no relief. Following three times of coronary angiography revealed that distal and small branch vessels still had stenosis, but was not required to revascularization. Due to serious headache resulted from sublingual or oral nitroglycerin; he had to take sublingual isosorbide dinitrate, from 20 mg to 150 mg each time, to obtain rapid relief from angina pectoris without doctor's consent. Followed up to April 2019, the patient has continued to take 100-150 mg sublingual isosorbide dinitrate for angina pectoris onset triggered by physical efforts, and has obtained remarkable relief within a few minutes, without blood pressure decrease and other side effects. Higher than recommend dosage of sublingual isosorbide dinitrate might establish better efficacy for angina pectoris in rarely patient.

Concomitant nitrates enhance clopidogrel response during dual anti-platelet therapy

BACKGROUND

Despite advances in modern anti-platelet strategies, clopidogrel still remains the cornerstone of dual anti-platelet therapy (DAPT) in patients undergoing percutaneous coronary interventions (PCI). There is some inconclusive evidence that response after clopidogrel may be impacted by concomitant medications, potentially affecting clinical outcomes. Sustained released nitrates (SRN) are commonly used together with clopidogrel in post-PCI setting for mild vasodilatation and nitric oxide-induced platelet inhibition.

METHODS

We prospectively enrolled 458 patients (64.5 ± 9.6 years old, and 73.4% males) following PCI undergoing DAPT with clopidogrel and aspirin. Platelet reactivity was assessed by the VerifyNow™ P2Y12 assay at the maintenance outpatient setting.

RESULTS

Concomitant SRN (n=266) significantly (p=0.008) enhanced platelet inhibition after DAPT (251.6 ± 80.9PRU) when compared (232.1 ± 73.5PRU) to the SRN-free (n=192) patients. Multivariate logistic regression analysis with the cut-off value of 253 PRU for defining heightened platelet reactivity confirmed independent correlation of more potent platelet inhibition during DAPT and use of SRN (Relative risk=1.675; Odds ratio [1.059-2.648]; p=0.027). In contrast, statins, calcium-channel blockers, beta blockers, angiotensin receptor blockers, ACE-inhibitors, diuretics, and anti-diabetic agents did not significantly impact platelet inhibition following DAPT.

CONCLUSION

The synergic ability of SRN to enhance response during DAPT may have important clinical implications with regard to better cardiovascular protection, but extra bleeding risks, requiring further confirmation in a large randomized study.

Effect of early treatment with anti-hypertensive drugs on short and long-term mortality in patients with an acute cardiovascular event

BACKGROUND

Acute cardiovascular events represent a therapeutic challenge. Blood pressure lowering drugs are commonly used and recommended in the early phase of these settings. This review analyses randomized controlled trial (RCT) evidence for this approach.

OBJECTIVES

To determine the effect of immediate and short-term administration of anti-hypertensive drugs on all-cause mortality, total non-fatal serious adverse events (SAE) and blood pressure, in patients with an acute cardiovascular event, regardless of blood pressure at the time of enrollment.

SEARCH STRATEGY

MEDLINE, EMBASE, and Cochrane clinical trial register from Jan 1966 to February 2009 were searched. Reference lists of articles were also browsed. In case of missing information from retrieved articles, authors were contacted.

SELECTION CRITERIA

Randomized controlled trials (RCTs) comparing anti-hypertensive drug with placebo or no treatment administered to patients within 24 hours of the onset of an acute cardiovascular event.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data and assessed risk of bias. Fixed effects model with 95% confidence intervals (CI) were used. Sensitivity analyses were also conducted.

MAIN RESULTS

Sixty-five RCTs (N=166,206) were included, evaluating four classes of anti-hypertensive drugs: ACE inhibitors (12 trials), beta-blockers (20), calcium channel blockers (18) and nitrates (18). Acute stroke was studied in 6 trials (all involving CCBs). Acute myocardial infarction was studied in 59 trials. In the latter setting immediate nitrate treatment (within 24 hours) reduced all-cause mortality during the first 2 days (RR 0.81, 95%CI [0.74,0.89], p<0.0001). No further benefit was observed with nitrate therapy beyond this point. ACE inhibitors did not reduce mortality at 2 days (RR 0.91,95%CI [0.82, 1.00]), but did after 10 days (RR 0.93, 95%CI [0.87,0.98] p=0.01). No other blood pressure lowering drug administered as an immediate treatment or short-term treatment produced a statistical significant mortality reduction at 2, 10 or >/=30 days. There was not enough data studying acute stroke, and there were no RCTs evaluating other acute cardiovascular events.

AUTHORS' CONCLUSIONS

Nitrates reduce mortality (4-8 deaths prevented per 1000) at 2 days when administered within 24 hours of symptom onset of an acute myocardial infarction. No mortality benefit was seen when treatment continued beyond 48 hours. Mortality benefit of immediate treatment with ACE inhibitors post MI at 2 days did not reach statistical significance but the effect was significant at 10 days (2-4 deaths prevented per 1000). There is good evidence for lack of a mortality benefit with immediate or short-term treatment with beta-blockers and calcium channel blockers for acute myocardial infarction.