Long-term prognostic factors of coronary artery disease patients after out-of-hospital cardiac arrest

Background

The long-term prognosis of survival in patients with out-of-hospital cardiac arrest (OHCA) with coronary artery disease (CAD) remains poor.

Methods

There were 2391 out-of-hospital cardiac arrest (OHCA) patients transferred to 2 hospitals. We included 405 cardiovascular arrest patients, who got return of spontaneous circulation (ROSC) from January 2015 to December 2018. Among them, 204 patients had CAD that caused OHCA (39%: multi-vessel disease, 19%: chronic total occlusion (CTO), 13%: vasospastic angina (VSA)). To predict mortality, we investigated patients' characteristics, pre-hospital information and findings of CAG.

Results

At 1-year later, 104 patients (51%) survived. Younger age (P<0.001), VF survivor (P<0.001), pre-hospital ROSC (P<0.001), bystander CPR (P=0.013), without ECMO (P<0.001), lower lactate level on admission (P<0.001), and higher geriatric nutritional risk index score (P<0.001) were associated with low 1-year mortality, while with ST-segment elevation (P=0.778), BMI level (P=0.344), and sex (0.401) were not. And in the findings of CAG, the past history of CAD (P=0.049), the higher number of coronary vessel disease (P=0.003) such as multi-vessel disease (P=0.022), higher SYNAX score (P=0.016), and larger infarct size (max CK level; P=0.013, max CK-MB level; P<0.001) were associated with high 1-year mortality. On the other hand, acute coronary syndrome (P=0.300), any coronary lesion (RCA (P=0.447), LAD (P=0.089), LCX (P=0.096), or LMT (P=0.842)), and with CTO lesion (P=0.140) were not associated. Zero-vessel disease (VSA, P=0.001) had lower mortality among the CAD patients. In the multivariate Cox proportional hazards model, age (hazards ratio; HR: 1.03, 95%confidence interval (CI) 1.00–1.06, P<0.001) and bystander CPR (HR: 0.36, 95% CI 0.20–0.65, P<0.001) were the independent predictors of mortality.

Conclusions

Younger age and pre-hospital support after OHCA with CAD were the predictors of low mortality. Pre-hospital information, systemic condition on arrival, or anatomical coronary complexity were important to predict low mortality.

Funding Acknowledgement

Type of funding sources: None.

Drug-coated balloon versus drug-eluting stent following orbital atherectomy for calcified coronary artery: one-year outcomes of a retrospective cohort study

Background

Percutaneous coronary intervention (PCI) for calcified coronary artery remains challenging in the drug-eluting stent (DES) era. The effectiveness of drug-coated balloons (DCBs) and orbital atherectomy system (OAS) is unknown.

Methods

In this retrospective, single-center study, we compared the use of DCBs with second- and third-generation DESs following orbital atherectomy (OA) for calcified de novo coronary lesions. All patients underwent PCI with intravascular imaging. The primary endpoint was major cardiac event, that was a composite of cardiac death, death for unknown cause, non-fatal myocardial infarction, or target lesion revascularization at 1 year.

Results

Between June 2018 and December 2019, 107 patients with coronary lesions were enrolled in this study and divided into two groups: 23 patients in DCB group and 84 patients in DES group. The post-procedure segment percentage diameter stenosis was 23.1% (interquartile range [IQR], 17.7 to 32.5) with DCB versus 14.4% (IQR, 10.0 to 21.2) with DES (P<0.001). Overall adverse event rate for PCI procedure was low: one dissection with DES group, no persistent slow/no-flow, and no perforation with both group. The primary endpoint was not significantly different between 2 groups [DES: 6.0% (5/84), DCB: 0.0% (0/23), log-rank P=0.24].

Conclusions

In calcified coronary artery disease, using DCB following OA is as safe and effective as using DES following OA with respect to 1-year clinical outcomes.

Funding Acknowledgement

Type of funding sources: None.

Neurological outcome at 30-day as an estimator of 1-year functional status after out-of-hospital cardiac arrest with post-encephalopathy

Background

Implantation of implantable cardioverter-defibrillators (ICD) for secondary prevention is fully recommended for those with an estimated survival over 1-year with a good functional status. However, we often face the difficulty to estimate the functional status and hesitate to implant ICD for patients with post-resuscitation encephalopathy.

Methods

There were 2391 out-of-hospital cardiac arrest (OHCA) patients transferred to 2 hospitals. We included 405 cardiovascular arrest patients, who got return of spontaneous circulation (ROSC) from January 2015 to December 2018. Among the patients, 343 patients could be considered to be implanted ICD for secondary prevention according to the initial waveform or the causes of OHCA. At 1-month later, 184 patients (54%) survived. To assess the association of functional status at 30-day and 1-year, we investigated patients' characteristics, pre-hospital information and clinical findings, and evaluated the neurological outcome according to the cerebral performance category (CPC) scale.

Results

At 1-month later, 145 patients (79%) survived with CPC≤2, and 39 patients (21%) survived with CPC>2. Bystander CPR (P=0.009), pre-hospital ROSC (P<0.001), low lactate level on admission (P=0.001), high geriatric nutritional risk index score (P<0.001) and without ECMO (P=0.002) were significantly associated with good neurological outcome at 30-day. The 1-year Kaplan-Meier event rate revealed significantly different survival rate (CPC>2 at 30-day:38.5%, vs CPC≤2 at 30-day:97.2%; P<0.001). In multivariate analysis, CPC scale at 30-day (OR 0.022; 95% CI 0.003–0.140; p<0.001) was the independent predictor of favorable neurological outcome at 1-year. Among the patients with CPC>2 at 30-day, only 3 patients (7.7%) of CPC=3 achieved the improvement of neurological outcome at 1-year (CPC≤2), while no patient of CPC=4 did. And one patient (2.5%) with CPC=3 was implanted ICD during the follow-up period. Twenty-five patients (64%) died of non-cardiovascular death with frailty of post-resuscitation encephalopathy after they were transferred to other hospital with the acceptation and intention of the do-not-attempt-resuscitation.

Conclusions

Neurological prognosis at 30-day after OHCA might be an estimator of 1-year functional status to guide us to implant ICD for secondary prevention.

Funding Acknowledgement

Type of funding sources: None.

Overexpression of cdk Inhibitor p16INK4a by adenovirus vector inhibits cardiac hypertrophy in vitro and in vivo: a novel strategy for the gene therapy of cardiac hypertrophy

Cardiac hypertrophy is one of the serious complications which increase mortality due to cardiovascular diseases. However, only a partial reduction of cardiac hypertrophy has been successful using current drug therapy. We demonstrate here reduction of cardiac hypertrophy in vitro and in vivo using an adenovirus vector encoding cyclin-dependent kinase (cdk) inhibitor p16INK4a. Adenovirus-mediated overexpression of cdk inhibitor p16INK4a completely inhibited cardiac myocyte hypertrophy induced by endothelin (ET)-1, as evaluated by [3H]leucine incorporation into the cells and mRNA levels of skeletal alpha -actin (SK-A) or atrial natriuretic peptide (ANP) as well as by morphometric analyses. We then evaluated whether p16INK4a can suppress left-ventricular (LV) hypertrophy induced by aortic banding (AOB) in rats. Catheter-mediated gene transfer of AxCAp16 was performed according to the method reported by Hajjar et al. LV overload was produced by coarctation of the ascending aorta immediately after inoculation of the heart with adenovirus. Two weeks after the procedure, the left ventricular weight/body weight ratio (LVW/BW) increased in the AOB+LacZ group in comparison to that in controls. However, LVW/BW was identical in the AOB+p16 group and controls. Histologic analysis revealed that p16INK4a inhibited hypertrophy of cardiac myocytes. These results suggest that G1 cell cycle regulators may restrict cardiac hypertrophy, and offer a novel strategy for the gene therapy of cardiac hypertrophy.

Cyclin A/cdk2 activation is involved in hypoxia-induced apoptosis in cardiomyocytes

Cardiomyocytes are terminally differentiated cells characterized as withdrawal cell-cycle machinery, but nonetheless they are known to express cell-cycle regulators. Because many proteins related to the cell cycle induce apoptosis in proliferating cells, we examined the involvement of these proteins in the apoptosis pathway in cardiomyocytes. Primary rat cardiomyocytes were exposed to a severe hypoxic condition to induce apoptosis. The apoptosis rate of cardiomyocytes increased to approximately 40% under 24 hours of hypoxia as evaluated by the TUNEL method. The cyclin A protein level assessed by immunoblot analysis accumulated in a time-dependent manner in cardiomyocytes, but there was no increase in nonmyocytes. Hypoxia increased the activity of cyclin A-associated kinase but not the activity of cyclin E-associated kinase, and the apoptosis was inhibited by infection of dominant-negative cdk2 adenovirus, suggesting that cyclin A and its associated kinase play significant roles in the apoptosis of cardiomyocytes. To investigate the cyclin A-mediated apoptosis, we infected cultured cells with cyclin A adenovirus. Apoptosis was induced in 63+/-12% of the infected cardiomyocytes in contrast to only 12+/-3% of the LacZ-infected control cells. In addition, the cells in the hypoxic condition showed an increase in caspase-3 activity and a subsequent decrease in p21(cip1/waf1) protein, which is partly cleaved by caspase-3. These findings confirm that cyclin A-associated kinase mediates hypoxia-induced apoptosis in cardiomyocytes, and they also suggest that additional elements of the cell-cycle-dependent machinery participate in this mechanism.

Role and relation of p70 S6 and extracellular signal-regulated kinases in the phenotypic changes of hypertrophy of cardiac myocytes

Cardiac hypertrophy is characterized by increased cardiomyocyte protein synthesis, increased cell volume, and a shift in cardiac-specific gene expression to fetal isoforms. Using neonatal rat cardiomyocytes stimulated with fetal calf serum (FCS) as a model for cardiac hypertrophy, the present study investigated the role of 2 signal transduction pathways, extracellular signal-regulated kinase (ERK) and p70S6 kinase (p70S6K), in the attendant phenotype changes. FCS evoked both ERK and p70S6K activity, peaking at 20-40min, and simultaneously increased cardiac myocyte protein synthesis (evaluated by [3H]leucine incorporation and total cellular protein content), cell size (evaluated by morphometry and fluorescence-activated cell sorter analysis) and expression of a fetal isoform of the muscle specific gene skeletal alpha-actin (SKA). Rapamycin, a specific inhibitor of the mammalian target of rapamycin (mTOR), which is an upstream signaling of p70S6K, completely inhibited FCS-induced cell size increases and protein synthesis, but had no effect on SKA mRNA expression. PD98059, which inhibited ERK activity, attenuated cardiac-specific gene expression in a dose-dependent manner, but had no influence on protein synthesis or cell size. These results indicate divergent roles for the ERK and p70S6K pathways in the phenotypic changes associated with cardiac hypertrophy.

G1 cyclins are involved in the mechanism of cardiac myocyte hypertrophy induced by angiotensin II

The importance of the cell cycle in proliferating cells is well known, but little is known about the role of cell cycle regulatory proteins in cardiac myocytes, which are fully differentiated cells. The present study determined, in vitro, the effect of angiotensin II (Ang II) treatment of neonatal rat cardiac myocytes on protein levels of cyclins and retinoblastoma gene product (pRb) phosphorylation. The role of G1 cyclin/cdk in Ang II-induced cardiac myocyte hypertrophy by overexpressing cdk inhibitor p21Cip1/Waf1 or p16INK4a was also examined using recombinant adenoviral vectors encoding these genes. Western blot analysis revealed that Ang II stimulated cyclin D1, D2, D3 and A protein levels in cardiac myocytes. Moreover, Ang II phosphorylated pRb on serine 780, which is known to occur in mitotic cells during cell cycle progression. Cultured cardiac myocytes treated with Ang II and infected with either control or recombinant adenovirus indicated that expression of p21 and p16 inhibited Ang II-induced cardiac myocyte hypertrophy, [3H]leucine incorporation into total cellular proteins, and skeletal alpha-actin (SK-A) and atrial natriuretic peptide (ANP) mRNA accumulation. Control virus had no effects on these parameters. These results suggest that G1 cyclins play an important role in cardiac myocyte hypertrophy stimulated by Ang II.

Calcitonin gene-related peptide (CGRP) and hypertrophy of cardiomyocytes

We studied whether calcitonin gene-related peptide (CGRP), a neuropeptide secreted from the sensory nervous supply to the myocardium, induces hypertrophy of cardiomyocytes in culture. CGRP increased the cell surface area of neonatal rat cardiomyocytes; the surface area of the cells was almost doubled by treatment with CGRP for 48 h. Furthermore, CGRP up-regulated mRNA expression for skeletal alpha-actin and atrial natriuretic peptides, which are genetic markers for cardiac hypertrophy. These results indicate that CGRP is a potent hypertrophic factor for cardiomyocytes.