Atrial natriuretic peptide (ANP) and brain (B-type) natriuretic peptide (BNP) are circulating hormones of cardiac origin that play an important role in the regulation of intravascular blood volume and vascular tone. The plasma concentrations of ANP and BNP are elevated in heart failure, and they are considered to compensate for heart failure because of their diuretic, natriuretic, and vasodilating actions and inhibitory effects on renin and aldosterone secretion. Evidence is also accumulating from recent work that ANP and BNP exert their cardioprotective functions not only as circulating hormones but also as local autocrine and/or paracrine factors. In studies using cultured neonatal myocytes and fibroblasts, exogenous administration of both ANP and ANP antagonists demonstrated that ANP has antihypertrophic and antifibrotic functions. Corroborating these in vitro results, mice lacking natriuretic receptor-A (NPR-A), the receptor for ANP and BNP, develop cardiac hypertrophy and fibrosis independent of their blood pressure. Recent studies also suggest that the intracardiac natriuretic peptides/cGMP system plays a counter-regulatory role against the intracardiac renin-angiotensin-aldosterone system and TGF-beta mediated pathway. In a clinical setting, human recombinant ANP and BNP may be used for a therapy of heart failure; however, further evaluation is required in the future.

/pdf/the-role-of-natriuretic-peptides-in-cardioprotection-41btvb1vzr.pdf

The role of natriuretic peptides in cardioprotection.

https://www.internationaljournalofcardiology.com/article/S0167-5273(04)00543-1/pdf

Myocardial ischemia/reperfusion-injury, a clinical view on a complex pathophysiological process

https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(07)61634-1.pdf

Human atrial natriuretic peptide and nicorandil as adjuncts to reperfusion treatment for acute myocardial infarction (J-WIND): two randomised trials

Atrial cardiocytes in the heart of mammals produce in a regulated manner the polypeptide hormones atrial natriuretic factor (ANF, ANP) and brain natriuretic peptide (BNP). The biological actions of ANF and BNP are similar; they include the modulation of systems that tend to increase extracellular fluid volume and blood pressure, such as the renin-angiotensin system and the sympathetic nervous system. Additionally, both hormones have potent growth-regulating properties. ANF and BNP signal by activating membrane-bound guanylyl cyclase receptors, leading to an increase in intracellular cGMP and thus affecting the activity of cGMP-regulated enzymes and ion channels. Under chronic hemodynamic overload, cardiac ANF and BNP synthesis and secretion are increased. This increase is viewed as a cardioprotective mechanism, given the beneficial effects of ANF and BNP on cardiac preload, afterload and cardiovascular growth. As discussed in this review, some basic facts regarding the synthesis and secretion of ANF and BNP and their peripheral effects remain to be clarified. Nevertheless, at the clinical level, the elevation of circulating ANF and BNP in heart failure or following acute coronary syndromes has been shown to have diagnostic and prognostic implications. Moreover, these peptides themselves hold promise as therapeutic agents in the treatment of heart failure. Additional pharmaceutical applications might be gleaned from current preclinical and clinical studies showing beneficial effects of ANF or BNP in the treatment of hypertension, bronchospasm and in tissue remodeling following acute myocardial infarction.

The endocrine function of the heart

Background
Intra-aortic balloon pump counterpulsation (IABP) is currently the most commonly used mechanical assist device for patients with cardiogenic shock due to acute myocardial infarction. Although there has been only limited evidence from randomised controlled trials, the previous guidelines of the American Heart Association/American College of Cardiology (AHA/ACC) and the European Society of Cardiology (ESC) strongly recommended the use of the IABP in patients with infarction-related cardiogenic shock on the basis of pathophysiological considerations, non-randomised trials and registry data. The recent guidelines downgraded the recommendation based on a meta-analysis which could only include non-randomised trials showing conflicting results. Up to now, there have been no guideline recommendations and no actual meta-analysis including the results of the large randomised multicentre IABP-SHOCK II Trial which showed no survival benefit with IABP support. This systematic review is an update of the review published in 2011.

Objectives
To evaluate, in terms of efficacy and safety, the effect of IABP versus non-IABP or other assist devices guideline compliant standard therapy on mortality and morbidity in patients with acute myocardial infarction complicated by cardiogenic shock.

Search methods
Searches of CENTRAL, MEDLINE (Ovid) and EMBASE (Ovid), LILACS, IndMed and KoreaMed, registers of ongoing trials and proceedings of conferences were updated in October 2013. Reference lists were scanned and experts in the field contacted to obtain further information. No language restrictions were applied.

Selection criteria
Randomised controlled trials on patients with acute myocardial infarction complicated by cardiogenic shock.

Data collection and analysis
Data collection and analysis were performed according to the published protocol. Individual patient data were provided for six trials and merged with aggregate data. Summary statistics for the primary endpoints were hazard ratios (HRs) and odds ratios (ORs) with 95% confidence intervals (CIs).

Main results
Seven eligible studies were identified from a total of 2314 references. One new study with 600 patients was added to the original review. Four trials compared IABP to standard treatment and three to other percutaneous left assist devices (LVAD). Data from a total of 790 patients with acute myocardial infarction and cardiogenic shock were included in the updated meta-analysis: 406 patients were treated with IABP and 384 patients served as controls; 339 patients were treated without assisting devices and 45 patients with other LVAD. The HR for all-cause 30-day mortality of 0.95 (95% CI 0.76 to 1.19) provided no evidence for a survival benefit. Different non-fatal cardiovascular events were reported in five trials. During hospitalisation, 11 and 4 out of 364 patients from the intervention groups suffered from reinfarction or stroke, respectively. Altogether 5 out of 363 patients from the control group suffered from reinfarction or stroke. Reocclusion was treated with subsequent re-revascularization in 6 out of 352 patients from the intervention group and 13 out of 353 patients of the control group. The high incidence of complications such as moderate and severe bleeding or infection in the control groups has to be attributed to interventions with other LVAD. Possible reasons for bias were more frequent in small studies with high cross-over rates, early stopping and the inclusion of patients with IABP at randomisation.

Authors' conclusions
Available evidence suggests that IABP may have a beneficial effect on some haemodynamic parameters. However, this did not result in survival benefits so there is no convincing randomised data to support the use of IABP in infarct-related cardiogenic shock.

Intra‐aortic balloon pump counterpulsation (IABP) for myocardial infarction complicated by cardiogenic shock

This study compared the hemodynamic effects of enhanced external counterpulsation and intra-aortic counterpulsation in patients with acute myocardial infarction. Results demonstrated similarity between these 2 methods, except enhanced external counterpulsation had a transient effect of increasing right atrial pressure, pulmonary capillary wedge pressure, and cardiac index.

Comparison of hemodynamic effects of enhanced external counterpulsation and intra-aortic balloon pumping in patients with acute myocardial infarction.

To evaluate the effects of synthetic human atrial natriuretic peptide (hANP) on myocardial reperfusion injury and left ventricular remodeling, 19 patients within 12 h of a first attack of anterior myocardial infarction (AMI) underwent intracoronary injection of 25 μg of hANP immediately after coronary angioplasty, combined with intravenous infusion of 0.025 μg · kg-1 · min-1 of hANP initiated on admission for 1 week (hANP group); 18 similar patients had saline administered (control group). The incidences of premature ventricular contraction, ventricular tachycardia and/or fibrillation in the hANP group were significantly less than in the control group after coronary angioplasty. Left ventricular ejection fraction was significantly greater and left ventricular end-diastolic volume index was significantly smaller 6 months after coronary angioplasty. Left ventricular regional wall motion of the infarcted segments significantly increased. Thus, hANP remarkably suppressed reperfusion phenomena and preserved left ventricular function through improvement of regional wall motion of the infarcted segments after coronary angioplasty. (Circ J 2003; 67: 443 - 448)

http://www.jstage.jst.go.jp/article/circj/67/5/67_5_443/_pdf

Administration of atrial natriuretic peptide attenuates reperfusion phenomena and preserves left ventricular regional wall motion after direct coronary angioplasty for acute myocardial infarction

nhanced external counterpulsation (EECP) is a noninvasive method of assisting the circulation, which enhances diastolic augmentation and systolic unloading by means of a pressurized air cuff around the patient’s legs that is maintained at approximately 300 mmHg during diastole. 1 In the United States, the effectiveness of this method in chronic angina has been reported, 2,3 and its effectiveness has been confirmed in a large-scale clinical trial. 4 It has been concluded that the increase in coronary blood flow by EECP treatment is mainly through diastolic augmentation, which is similar to the effect on the arterial system by intraaortic balloon pumping (IABP), but EECP also has an effect on venous return. It can be implemented immediately, and is noninvasive without risk of bleeding or infection, which is a great advantage compared with IABP. 5,6 It is anticipated that EECP will help improve the circulation in patients with acute heart failure and acute coronary syndrome. We previously reported that in patients with acute myocardial infarction (AMI) EECP produced diastolic augmentation similar to IABP, but increased preload and the cardiac index (CI) with increased venous return, which is different to IABP. 7 In this study, we used EECP in patients with AMI and observed the changes in neurohumoral factors, as well as the hemodynamic effects, to investigate its mechanism and effects on left cardiac function.

http://www.counterpulsation.co.za/files/J2004---Taguchi---Effects-of-EECP-on-Hemodynamics-and-Its-Me.pdf

Effects of enhanced external counterpulsation on hemodynamics and its mechanism.

Background The beneficial effect of percutaneous coronary intervention (PCI) using stents for acute myocardial infarction (AMI) has already been demonstrated, but there is the problem that mechanical microvascular occlusion can occur because of thrombus/atheroma embolization when the PCI was performed. The aim of the present study was to retrospectively test and compare the effects of an aspiration catheter or distal embolic protection with a distal occlusion balloon catheter to prevent peripheral vascular embolization. Methods and Results The subjects consisted of 135 patients who underwent PCI with stenting within 12 h of the onset of chest pain caused by their first AMI. They were divided into 2 groups; the aspiration group, consisted of 81 consecutively seen patients who underwent aspiration catheter treatment between January 2001 and May 2002, and the distal protection group was the next group of 54 consecutively seen patients treated with a distal protection device between June 2002 and February 2003. The results were as follows. Thrombolysis in Myocardial Infarction (TIMI) score of 3 was obtained significantly more frequently in the distal protection group (94.4%) than in the aspiration group (79.0%). Additionally, the intensity of the cardiac muscle stain (blush score) was evaluated on coronary angiography and the rate of cases showing a blush score of 3, which indicates favorable blood perfusion at the tissue level, in the distal protection group (56.6%) was significantly greater than in the aspiration group (33.3%, p<0.01). The time to peak blood concentration of creatinine kinase was also significantly shorter in the distal protection group. Conclusions The distal embolism protection method is superior to the aspiration method for prevention of embolization after PCI with stenting for AMI, in terms of tissue level reperfusion in myocardial recanalization therapy. (Circ J 2005; 69: 49 - 54)

Comparison of the effects of a distal embolic protection device and an aspiration catheter during percutaneous coronary intervention in patients with acute myocardial infarction.

Isao Taguchi

Papers

Comparison of hemodynamic effects of enhanced external counterpulsation and intra-aortic balloon pumping in patients with acute myocardial infarction.

Administration of atrial natriuretic peptide attenuates reperfusion phenomena and preserves left ventricular regional wall motion after direct coronary angioplasty for acute myocardial infarction

Effects of enhanced external counterpulsation on hemodynamics and its mechanism.

Comparison of the effects of a distal embolic protection device and an aspiration catheter during percutaneous coronary intervention in patients with acute myocardial infarction.