IMPORTANCE Very short mandatory dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) with a drug-eluting stent may be an attractive option. OBJECTIVE To test the hypothesis of noninferiority of 1 month of DAPT compared with standard 12 months of DAPT for a composite end point of cardiovascular and bleeding events. DESIGN, SETTING, AND PARTICIPANTS Multicenter, open-label, randomized clinical trial enrolling 3045 patients who underwent PCI at 90 hospitals in Japan from December 2015 through December 2017. Final 1-year clinical follow-up was completed in January 2019. INTERVENTIONS Patients were randomized either to 1 month of DAPT followed by clopidogrel monotherapy (n=1523) or to 12 months of DAPT with aspirin and clopidogrel (n=1522). MAIN OUTCOMES AND MEASURES The primary end point was a composite of cardiovascular death, myocardial infarction (MI), ischemic or hemorrhagic stroke, definite stent thrombosis, or major or minor bleeding at 12 months, with a relative noninferiority margin of 50%. The major secondary cardiovascular end point was a composite of cardiovascular death, MI, ischemic or hemorrhagic stroke, or definite stent thrombosis and the major secondary bleeding end point was major or minor bleeding. RESULTS Among 3045 patients randomized, 36 withdrew consent; of 3009 remaining, 2974 (99%) completed the trial. One-month DAPT was both noninferior and superior to 12-month DAPT for the primary end point, occurring in 2.36% with 1-month DAPT and 3.70% with 12-month DAPT (absolute difference, −1.34% [95% CI, −2.57% to −0.11%]; hazard ratio [HR], 0.64 [95% CI, 0.42-0.98]), meeting criteria for noninferiority (P < .001) and for superiority (P = .04). The major secondary cardiovascular end point occurred in 1.96% with 1-month DAPT and 2.51% with 12-month DAPT (absolute difference, −0.55% [95% CI, −1.62% to 0.52%]; HR, 0.79 [95% CI, 0.49-1.29]), meeting criteria for noninferiority (P = .005) but not for superiority (P = .34). The major secondary bleeding end point occurred in 0.41% with 1-month DAPT and 1.54% with 12-month DAPT (absolute difference, −1.13% [95% CI, −1.84% to −0.42%]; HR, 0.26 [95% CI, 0.11-0.64]; P = .004 for superiority). CONCLUSIONS AND RELEVANCE Among patients undergoing PCI, 1 month of DAPT followed by clopidogrel monotherapy, compared with 12 months of DAPT with aspirin and clopidogrel, resulted in a significantly lower rate of a composite of cardiovascular and bleeding events, meeting criteria for both noninferiority and superiority. These findings suggest that a shorter duration of DAPT may provide benefit, although given study limitations, additional research is needed in other populations.
Mitochondria are one of the enzymatic sources of reactive oxygen species (ROS) and could also be a major target for ROS-mediated damage. We hypothesized that ROS may induce mitochondrial DNA (mtDNA) damage, which leads to defects of mtDNA-encoded gene expression and respiratory chain complex enzymes and thus may contribute to the progression of left ventricular (LV) remodeling and failure after myocardial infarction (MI). In a murine model of MI and remodeling created by the left anterior descending coronary artery ligation for 4 weeks, the LV was dilated and contractility was diminished. Hydroxyl radicals, which originated from the superoxide anion, and lipid peroxide formation in the mitochondria were both increased in the noninfarcted LV from MI mice. The mtDNA copy number relative to the nuclear gene (18S rRNA) preferentially decreased by 44% in MI by a Southern blot analysis, associated with a parallel decrease (30% to 50% of sham) in the mtDNA-encoded gene transcripts, including the subunits of complex I (ND1, 2, 3, 4, 4L, and 5), complex III (cytochrome b), complex IV (cytochrome c oxidase), and rRNA (12S and 16S). Consistent with these molecular changes, the enzymatic activity of complexes I, III, and IV decreased in MI, whereas, in contrast, complex II and citrate synthase, encoded only by nuclear DNA, both remained at normal levels. An intimate link among ROS, mtDNA damage, and defects in the electron transport function, which may lead to an additional generation of ROS, might play an important role in the development and progression of LV remodeling and failure.
Abstract-Experimental and clinical studies have suggested an increased production of reactive oxygen species (ROS) in the failing myocardium. The present study aimed to obtain direct evidence for increased ROS and to determine the contribution of superoxide anion ( ⅐ O 2 Ϫ ), H 2 O 2 , and hydroxy radical ( ⅐ OH) in failing myocardial tissue. Heart failure was produced in adult mongrel dogs by rapid ventricular pacing at 240 bpm for 4 weeks. To assess the production of ROS directly, freeze-clamped myocardial tissue homogenates were reacted with the nitroxide radical, 4-hydroxy-2,2,6,6,-tetramethyl-piperidine-N-oxyl, and its spin signals were detected by electron spin resonance spectroscopy. The rate of electron spin resonance signal decay, proportional to ⅐ OH level, was significantly increased in heart failure, which was inhibited by the addition of dimethylthiourea ( ⅐ OH scavenger) into the reaction mixture. Increased ⅐ OH in the failing heart was abolished to the same extent in the presence of desferrioxamine (iron chelator
Background-Tumor necrosis factor-␣ (TNF-␣) and angiotensin II (Ang II) are implicated in the development and further progression of heart failure, which might be, at least in part, mediated by the production of reactive oxygen species (ROS). However, the cause and consequences of this agonist-mediated ROS production in cardiac myocytes have not been well defined. Recently, we demonstrated that increased ROS production was associated with mitochondrial DNA (mtDNA) damage and dysfunction in failing hearts. We thus investigated whether the direct exposure of cardiac myocytes to TNF-␣ and Ang II in vitro could induce mtDNA damage via production of ROS. Methods and Results-TNF-␣ increased ROS production within cultured neonatal rat ventricular myocytes after 1 hour, as assessed by 2Ј,7Ј-dichlorofluorescin diacetate fluorescence microscopy. TNF-␣ also decreased mtDNA copy number by Southern blot analysis in association with complex III activity, which was prevented in the presence of the antioxidant ␣-tocopherol. A direct exposure of myocytes to H 2 O 2 caused a similar decrease in mtDNA copy number. In contrast, Ang II did not affect mtDNA copy number, despite the similar increase in ROS production. TNF-␣-mediated ROS production and a decrease in mtDNA copy number were inhibited by the sphingomyelinase inhibitor D609. Furthermore, N-acetylsphingosine (C2-ceramide), a synthetic cell-permeable ceramide analogue, increased myocyte ROS production, suggesting that TNF-␣-mediated ROS production and subsequent mtDNA damage were mediated by the sphingomyelin-ceramide signaling pathway. Conclusions-The intimate link between TNF-␣, ROS, and mtDNA damage might play an important role in myocardial remodeling and failure.
Abstract-Oxidative stress might play an important role in the progression of left ventricular (LV) remodeling and failure that occur after myocardial infarction (MI). We determined whether reactive oxygen species (ROS) are increased in the LV remodeling and failure in experimental MI with the use of electron spin resonance spectroscopy and whether the long-term administration of dimethylthiourea (DMTU), hydroxyl radical ( ⅐ OH) scavenger, could attenuate these changes. We studied 3 groups of mice: sham-operated (sham), MI, and MI animals that received DMTU (MIϩDMTU). Drugs were administered to the animals daily via intraperitoneal injection for 4 weeks. ⅐ OH was increased in the noninfarcted myocardium from MI animals, which was abolished in MIϩDMTU. Fractional shortening was depressed by 65%, LV chamber diameter was increased by 53%, and the thickness of noninfarcted myocardium was increased by 37% in MI. MIϩDMTU animals had significantly better LV contractile function and smaller increases in LV chamber size and hypertrophy than MI animals. Changes in myocyte cross-sectional area determined with LV mid-free wall specimens were concordant with the wall thickness data. Collagen volume fraction of the noninfarcted myocardium showed significant increases in the MI, which were also attenuated with DMTU. Myocardial matrix metalloproteinase-2 activity, measured with gelatin zymography, was increased with MI after 7 and 28 days, which was attenuated in MIϩDMTU. Thus, the attenuation of increased myocardial ROS and metalloproteinase activity with DMTU may contribute, at least in part, to its beneficial effects on LV remodeling and failure. Therapies designed to interfere with oxidative stress might be beneficial to prevent myocardial failure. (Circ Res. 2000;87:392-398.)Key Words: antioxidant Ⅲ radicals Ⅲ heart failure Ⅲ myocardial infarction Ⅲ remodeling M yocardial infarction (MI) frequently produces left ventricular (LV) dilatation and hypertrophy of the noninfarcted myocardium. 1 These changes in LV geometry, referred to as remodeling, contribute to the development of depressed cardiac performance. 2 Thus, surviving patients with MI are at an increased risk for occurrence of heart failure (HF), reinfarction, arrhythmia, and sudden cardiac death. 2 LV remodeling is caused by the side-to-side slippage of cardiac myocytes at the infarcted region and the hypertrophic response of the noninfarcted myocytes, resulting in a progressive increase in the chamber diameter. 3 The underlying mechanisms responsible for these processes have been attributed to hemodynamic stress as well as the activation of neurohumoral factors, including the renin-angiotensin system. However, the details of contributing factors in LV remodeling remain to be elucidated.Reactive oxygen species (ROS) can produce myocardial contractile dysfunction and structural damage. 4 There is growing evidence that ROS are increased in HF and may contribute to disease progression. 5,6 Hill and Singal 7 showed that antioxidant enzyme activities are decreased and th...
Background-Short-term administration of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, statins, has been shown to attenuate ischemia-reperfusion injury. However, the effects of long-term administration of statins on left ventricular (LV) remodeling and failure after myocardial infarction remain unknown. Methods and Results-Mice were subjected to coronary artery ligation and were treated for 4 weeks with vehicle or fluvastatin (10 mg/kg per day PO). Fluvastatin increased survival (61% versus 86%; PϽ0.05) without affecting the infarct size (52Ϯ2% versus 49Ϯ3%; PϭNS). Fluvastatin not only attenuated LV dilatation but also decreased LV end-diastolic pressure and lung weight. Furthermore, it reduced cardiac myocyte hypertrophy and interstitial fibrosis of the noninfarcted LV and also improved LV ejection performance. LV matrix metalloproteinase (MMP)-2 and MMP-13 were increased in myocardial infarction, which was attenuated in fluvastatin-treated mice. Conclusions-Fluvastatin increased survival in a murine model of postinfarct heart failure, which was associated with the amelioration of LV structural remodeling and contractile failure. Moreover, these effects were associated with the attenuation of increased MMP activity. Thus, long-term treatment with fluvastatin might be beneficial also in patients with heart failure and might improve their long-term survival.
Coronary risk factors, including age, hypertension, diabetes mellitus, hyperlipidemia, and smoking, are associated with enhanced oxidative stress, which is implicated as a potential mechanism for atherogenesis and atherosclerotic cardiovascular diseases. Male sex is one of the well-known cardiovascular risk factors. We tested the hypothesis that oxidative stress is greater in men than in women. Plasma thiobarbituric acid-reactive substances (TBARS) and urinary 8-isoprostaglandin F2alpha (8-iso-PGF2alpha) were measured in 52 young men and 51 age-matched women. The subjects were healthy, were not smokers, and were not taking any medications or vitamins. Age, blood pressure, plasma cholesterol, and glucose did not differ between the groups. Baseline TBARS (2.32 +/- 0.11 [men] versus 1.87 +/- 0.09 [women] nmol/mL, P<0.01) and 8-iso-PGF2alpha (292 +/- 56 [men] versus 164 +/- 25 [women] pg/mg creatinine, P<0.05) were higher in men than in women. Supplementation of antioxidant vitamins for 4 weeks in men produced a significant reduction in TBARS and 8-iso-PGF2alpha by 34% (P<0.01) and 48% (P<0.05), respectively. Plasma superoxide dismutase, catalase, and vitamin E levels were comparable between the groups. Enhanced oxidative stress in men may provide a biochemical link between male sex and atherosclerotic diseases related to oxidative stress.
Background-Increased expression of monocyte chemoattractant protein-1 (MCP-1) has recently been described in clinical and experimental failing heart. However, its pathophysiological significance in heart failure remains obscure. We thus determined whether MCP-1 is increased in post-myocardial infarction (MI) hearts and its blockade can attenuate the development of left ventricular (LV) remodeling and failure. Methods and Results-Anterior MI was produced in mice by ligating the left coronary artery. After 4 weeks, MI mice exerted LV dilatation and contractile dysfunction in association with myocyte hypertrophy and interstitial fibrosis of noninfarcted LV. MCP-1 mRNA levels were increased by 40-fold in noninfarcted LV 1 day after ligation, which persisted until 28 days. To block the MCP-1 signals, an N-terminal deletion mutant of the human MCP-1 gene was transfected into the limb skeletal muscle 3 days before and 14 days after ligation. This method improved the survival rate of mice with MI at 4 weeks (61% versus 87%, PϽ0.05) as well as attenuated LV cavity dilatation and contractile dysfunction, interstitial fibrosis, recruitment of macrophages, and myocardial gene expression of tumor necrosis factor-␣ and transforming growth factor- compared with the nontreated MI mice despite the comparable infarct size calculated as percent LV circumference. Conclusions-The
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