Pathogenic SLC25A26 variants impair SAH transport activity causing mitochondrial disease.

The SLC25A26 gene encodes a mitochondrial inner membrane carrier that transports S-adenosylmethionine (SAM) into the mitochondrial matrix in exchange for S-adenosylhomocysteine (SAH). SAM is the predominant methyl-group donor for most cellular methylation processes, of which SAH is produced as a by-product. Pathogenic, biallelic SLC25A26 variants are a recognized cause of mitochondrial disease in children, with a severe neonatal onset caused by decreased SAM transport activity. Here, we describe two, unrelated adult cases, one of whom presented with recurrent episodes of severe abdominal pain and metabolic decompensation with lactic acidosis. Both patients had exercise intolerance and mitochondrial myopathy associated with biallelic variants in SLC25A26, which led to marked respiratory chain deficiencies and mitochondrial histopathological abnormalities in skeletal muscle that are comparable to those previously described in early-onset cases. We demonstrate using both mouse and fruit fly models that impairment of SAH, rather than SAM, transport across the mitochondrial membrane is likely the cause of this milder, late-onset phenotype. Our findings associate a novel pathomechanism with a known disease-causing protein and highlight the quests of precision medicine in optimizing diagnosis, therapeutic intervention and prognosis.

Identifying opportunities to advance health equity in interventional cardiology: Structural heart disease.

Health care practices are influenced by variety of factors. These factors that include social determinants, race and ethnicity, and gender not only affect access to health care but can also affect quality of care and patient outcomes. These are a source of health care disparities. This article acknowledges that these disparities exist in getting optimal care in structural heart disease, reviews the literature and proposes steps that can help reduce these disparities on personal and committee levels.

Relationship between predicting bleeding complication in patients undergoing stent implantation and subsequent dual antiplatelet therapy (PRECISE-DAPT) score and mortality among patients with atrial fibrillation undergoing percutaneous coronary intervention.

BACKGROUND: The predicting bleeding complication in patients undergoing stent implantation and subsequent dual antiplatelet therapy, PRECISE-DAPT (P-DAPT) score has been validated in large cohorts as an effective tool in predicting bleeding complication after dual antiplatelet therapy (DAPT) as well as in predicting in-hospital mortality. The implication of using this score to predict outcomes, including mortality in patients with atrial fibrillation (AF) undergoing PCI is unknown. OBJECTIVE: Role of P-DAPT score to study clinical outcomes, including mortality, hospitalization, and major bleeding, particularly among patients with AF. METHODS: This is a retrospective observational study of 18,850 consecutive patients who underwent percutaneous coronary intervention (PCI) across a large multihospital healthcare system from 2010 to 2019. Patients were stratified into four groups depending on the presence or absence of AF and P-DAPT score, with score ≥ 25 defined as high risk. The primary outcome was all-cause mortality. The secondary outcomes evaluated were hospitalization and major bleeding. RESULTS: In the unadjusted analyses, a P-DAPT score ≥ 25, in both AF and non-AF population, was associated with increased mortality, hospitalization, and bleeding. After adjusting for baseline covariates, no significant differences in major bleeding risk were found across the four groups. However, a P-DAPT score of ≥25 in AF patients was associated with a higher risk for hospitalizations related to cardiovascular causes (HR: 2.15 95% CI 2.00-2.3, p < .0001). Among AF patients, P-DAPT score ≥ 25 was found to be strongly associated with mortality (HR 3.5; 95% CI 2.95-4.25, p < .0001) as compared with AF patients with score < 25 (HR 1.18, 95% CI 0.88-1.54, p = .26). CONCLUSION: In this large cohort of patients undergoing PCI, the P-DAPT score can help to identify patients at high risk for long-term mortality, particularly among those with atrial fibrillation.

The natural history of infantile mitochondrial DNA depletion syndrome due to RRM2B deficiency.

PURPOSE: Mitochondrial DNA (mtDNA) depletion syndrome (MDDS) encompasses a group of genetic disorders of mtDNA maintenance. Mutation of RRM2B is an uncommon cause of infantile-onset encephalomyopathic MDDS. Here we describe the natural history of this disease. METHODS: Multinational series of new genetically confirmed cases from six pediatric centers. RESULTS: Nine new cases of infantile-onset RRM2B deficiency, and 22 previously published cases comprised a total cohort of 31 patients. Infants presented at a mean of 1.95 months with truncal hypotonia, generalized weakness, and faltering growth. Seizures evolved in 39% at a mean of 3.1 months. Non-neurological manifestations included respiratory distress/failure (58%), renal tubulopathy (55%), sensorineural hearing loss (36%), gastrointestinal disturbance (32%), eye abnormalities (13%), and anemia (13%). Laboratory features included elevated lactate (blood, cerebrospinal fluid (CSF), urine, magnetic resonance (MR), spectroscopy), ragged-red and cytochrome c oxidase-deficient fibers, lipid myopathy, and multiple oxidative phosphorylation enzyme deficiencies in skeletal muscle. Eight new RRM2B variants were identified. Patients with biallelic truncating variants had the worst survival. Overall survival was 29% at 6 months and 16% at 1 year. CONCLUSIONS: Infantile-onset MDDS due to RRM2B deficiency is a severe disorder with characteristic clinical features and extremely poor prognosis. Presently management is supportive as there is no effective treatment. Novel treatments are urgently needed.

Distal myopathy with cachexia: an unrecognised phenotype caused by dominantly-inherited mitochondrial polymerase γ mutations.

BACKGROUND: The myopathy associated with mutations in the nuclear-encoded mitochondrial DNA maintenance gene POLG, coding for the catalytic subunit of DNA polymerase, is typically proximal with early ophthalmoplegia. RESULTS: We report two unrelated patients in whom a distal, mainly upper limb, myopathy was the predominant and early clinical feature. One patient also suffered with marked cachexia. DNA genomic sequence analysis identified novel dominant heterozygous missense POLG mutations (Leu896Arg and Tyr951His) located within the conserved catalytic polymerase domain of the protein in both cases. CONCLUSIONS: Distal upper limb myopathy/cachexia is not previously described with dominant POLG mutations and our observations further highlight the diverse clinical spectrum of POLG-related mitochondrial disorders. These data indicate that dominant POLG mutations should be considered in the differential diagnosis of distal upper limb predominant myopathy.

Prospective study of POLG mutations presenting in children with intractable epilepsy: prevalence and clinical features.

PURPOSE: To assess the frequency and clinical features of childhood-onset intractable epilepsy caused by the most common mutations in the POLG gene, which encodes the catalytic subunit of mitochondrial DNA polymerase gamma. METHODS: Children presenting with nonsyndromic intractable epilepsy of unknown etiology but without documented liver dysfunction at presentation were eligible for this prospective, population-based study. Blood samples were analyzed for the three most common POLG mutations. If any of the three tested mutations were found, all the exons and the exon-intron boundaries of the POLG gene were sequenced. In addition, we retrospectively reviewed the notes of patients presenting with intractable epilepsy in which we had found POLG mutations. All available clinical data were collected by questionnaire and by reviewing the medical records. KEY FINDINGS: We analyzed 213 blood DNA samples from patients fulfilling the inclusion criteria of the prospective study. Among these, five patients (2.3%) were found with one of the three common POLG mutations as homozygous or compound heterozygous states. In addition, three patients were retrospectively identified. Seven of the eight patients had either raised cerebrospinal fluid (CSF) lactate (n = 3) or brain magnetic resonance imaging (MRI) changes (n = 4) at presentation with intractable epilepsy. Three patients later developed liver dysfunction, progressing to fatal liver failure in two without previous treatment with sodium valproate (VPA). Furthermore, it is worth mentioning that one patient presented first with an autism spectrum disorder before seizures emerged. SIGNIFICANCE: Mutations in POLG are an important cause of early and juvenile onset nonsyndromic intractable epilepsy with highly variable associated manifestations including autistic features. This study emphasizes that genetic testing for POLG mutations in patients with nonsyndromic intractable epilepsies is very important for clinical diagnostics, genetic counseling, and treatment decisions because of the increased risk for VPA-induced liver failure in patients with POLG mutations. We recommend POLG gene testing for patients with intractable seizures and at least one elevated CSF lactate or suggestive brain MRI changes (predominantly abnormal T2 -weighted thalamic signal) with or without status epilepticus, epilepsia partialis continua, or liver manifestations typical for Alpers disease, especially when the disease course is progressive.

Adults with RRM2B-related mitochondrial disease have distinct clinical and molecular characteristics.

Mutations in the nuclear-encoded mitochondrial maintenance gene RRM2B are an important cause of familial mitochondrial disease in both adults and children and represent the third most common cause of multiple mitochondrial DNA deletions in adults, following POLG [polymerase (DNA directed), gamma] and PEO1 (now called C10ORF2, encoding the Twinkle helicase) mutations. However, the clinico-pathological and molecular features of adults with RRM2B-related disease have not been clearly defined. In this multicentre study of 26 adult patients from 22 independent families, including five additional cases published in the literature, we show that extra-ocular neurological complications are common in adults with genetically confirmed RRM2B mutations. We also demonstrate a clear correlation between the clinical phenotype and the underlying genetic defect. Myopathy was a prominent manifestation, followed by bulbar dysfunction and fatigue. Sensorineural hearing loss and gastrointestinal disturbance were also important findings. Severe multisystem neurological disease was associated with recessively inherited compound heterozygous mutations with a mean age of disease onset at 7 years. Dominantly inherited heterozygous mutations were associated with a milder predominantly myopathic phenotype with a later mean age of disease onset at 46 years. Skeletal muscle biopsies revealed subsarcolemmal accumulation of mitochondria and/or cytochrome c oxidase-deficient fibres. Multiple mitochondrial DNA deletions were universally present in patients who underwent a muscle biopsy. We identified 18 different heterozygous RRM2B mutations within our cohort of patients, including five novel mutations that have not previously been reported. Despite marked clinical overlap between the mitochondrial maintenance genes, key clinical features such as bulbar dysfunction, hearing loss and gastrointestinal disturbance should help prioritize genetic testing towards RRM2B analysis, and sequencing of the gene may preclude performance of a muscle biopsy.

Genetic testing for mitochondrial disease: the United Kingdom best practice guidelines.

Primary mitochondrial disease describes a diverse group of neuro-metabolic disorders characterised by impaired oxidative phosphorylation. Diagnosis is challenging; >350 genes, both nuclear and mitochondrial DNA (mtDNA) encoded, are known to cause mitochondrial disease, leading to all possible inheritance patterns and further complicated by heteroplasmy of the multicopy mitochondrial genome. Technological advances, particularly next-generation sequencing, have driven a shift in diagnostic practice from 'biopsy first' to genome-wide analyses of blood and/or urine DNA. This has led to the need for a reference framework for laboratories involved in mitochondrial genetic testing to facilitate a consistent high-quality service. In the United Kingdom, consensus guidelines have been prepared by a working group of Clinical Scientists from the NHS Highly Specialised Service followed by national laboratory consultation. These guidelines summarise current recommended technologies and methodologies for the analysis of mtDNA and nuclear-encoded genes in patients with suspected mitochondrial disease. Genetic testing strategies for diagnosis, family testing and reproductive options including prenatal diagnosis are outlined. Importantly, recommendations for the minimum levels of mtDNA testing for the most common referral reasons are included, as well as guidance on appropriate referrals and information on the minimal appropriate gene content of panels when analysing nuclear mitochondrial genes. Finally, variant interpretation and recommendations for reporting of results are discussed, focussing particularly on the challenges of interpreting and reporting mtDNA variants.

Outcomes in Multivessel Coronary Disease Stratified by The Society of Thoracic Surgeons Risk.

BACKGROUND: Surgical risk stratified outcomes after contemporary revascularization strategies have not been well described. We report these outcomes in patients undergoing percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) for multivessel coronary disease. METHODS: A total of 5836 patients with multivessel disease who underwent CABG (n = 4420) or PCI (n = 1416) were included in this retrospective observational analysis. Data were stratified based on The Society of Thoracic Surgeons risk score. A score less than 4% was considered low risk and a score greater than or equal to 4% was considered intermediate-high risk. Outcomes included mortality, inpatient readmissions, and repeat revascularizations. RESULTS: In the CABG population, 3863 (87.3%) were low risk and 557 (12.6%) were intermediate-high risk. The 5-year mortality for the low-risk cohort was 10.9% (95% confidence interval [CI], 9.83%-12.05%), and for the intermediate-high-risk cohort it was 40.1% (95% CI, 35.76%-44.54%). Among those undergoing PCI, 1163 (82.1%) were low risk, while 249 (17.6%) were intermediate-high risk. The 5-year mortality for the low-risk cohort was 21.6% (95% CI, 19.10%-24.26%), and for the intermediate-high-risk cohort it was 61.8% (95% CI, 54.72%-68.70%). CONCLUSIONS: This study reports outcomes stratified by surgical risk after PCI or CABG in patients with multivessel coronary disease. These data can help guide the revascularization strategy choice for individual patients.

A comparison of bare-metal and drug-eluting stents for off-label indications.

BACKGROUND: Recent reports suggest that off-label use of drug-eluting stents is associated with an increased incidence of adverse events. Whether the use of bare-metal stents would yield different results is unknown. METHODS: We analyzed data from 6551 patients in the National Heart, Lung, and Blood Institute Dynamic Registry according to whether they were treated with drug-eluting stents or bare-metal stents and whether use was standard or off-label. Patients were followed for 1 year for the occurrence of cardiovascular events and death. Off-label use was defined as use in restenotic lesions, lesions in a bypass graft, left main coronary artery disease, or ostial, bifurcated, or totally occluded lesions, as well as use in patients with a reference-vessel diameter of less than 2.5 mm or greater than 3.75 mm or a lesion length of more than 30 mm. RESULTS: Off-label use occurred in 54.7% of all patients with bare-metal stents and 48.7% of patients with drug-eluting stents. As compared with patients with bare-metal stents, patients with drug-eluting stents had a higher prevalence of diabetes, hypertension, renal disease, previous percutaneous coronary intervention and coronary-artery bypass grafting, and multivessel coronary artery disease. One year after intervention, however, there were no significant differences in the adjusted risk of death or myocardial infarction in patients with drug-eluting stents as compared with those with bare-metal stents, whereas the risk of repeat revascularization was significantly lower among patients with drug-eluting stents. CONCLUSIONS: Among patients with off-label indications, the use of drug-eluting stents was not associated with an increased risk of death or myocardial infarction but was associated with a lower rate of repeat revascularization at 1 year, as compared with bare-metal stents. These findings support the use of drug-eluting stents for off-label indications.

Novel method for transaxillary Impella 5.0 implantation in patients with tortuous arterial anatomy.

A novel method of transaxillary Impella 5.0 implantation utilizing a vascular sheath can overcome difficult arterial anatomy and provide mechanical support for patients in critical cardiogenic shock.

Depletion of mitochondrial DNA in fibroblast cultures from patients with POLG1 mutations is a consequence of catalytic mutations.

We investigated clinical and cellular phenotypes of 24 children with mutations in the catalytic (alpha) subunit of the mitochondrial DNA (mtDNA) gamma polymerase (POLG1). Twenty-one had Alpers syndrome, the commonest severe POLG1 autosomal recessive phenotype, comprising hepatoencephalopathy and often mtDNA depletion. The cellular mtDNA content reflected the genotype more closely than did clinical features. Patients with tissue depletion of mtDNA all had at least one allele with either a missense mutation in a catalytic domain or a nonsense mutation. Four out of 12 patients exhibited a progressive, mosaic pattern of mtDNA depletion in cultured fibroblasts. All these patients had mutations in a catalytic domain in both POLG1 alleles, in either the polymerase or exonuclease domain or both. The tissue mtDNA content of patients who had two linker mutations was normal, and their phenotypes the mildest. Epilepsy and/or movement disorder were major features in all 21. Previous studies have implicated replication stalling as a mechanism for mtDNA depletion. The mosaic cellular depletion that we have demonstrated in cell cultures may be a manifestation of severe replication stalling. One patient with a severe cellular and clinical phenotype was a compound heterozygote with POLG1 mutations in the polymerase and exonuclease domain intrans. This suggests that POLG1 requires both polymerase and 3'-5' exonuclease activity in the same molecule. This is consistent with current functional models for eukaryotic DNA polymerases, which alternate between polymerizing and editing modes, as determined by competition between these two active sites for the 3' end of the DNA.

Does graft construct lengthening at the fixations cause an increase in anterior laxity following anterior cruciate ligament reconstruction in vivo?

A millimeter-for-millimeter relation between an increase in length of an anterior cruciate ligament graft construct and an increase in anterior laxity has been demonstrated in multiple in vitro studies. Based on this relation, a 3 mm increase in length of the graft construct following surgery could manifest as a 3 mm increase in anterior laxity in vivo, which is considered clinically unstable. Hence, the two primary objectives were to determine whether the millimeter-for-millimeter relation exists in vivo for slippage-resistant fixation of a soft-tissue graft and, if it does not exist, then to what extent the increase in stiffness caused by biologic healing of the graft to the bone tunnel offsets the potential increase in anterior laxity resulting from lengthening at the sites of fixation. Sixteen subjects were treated with a fresh-frozen, nonirradiated, nonchemically processed tibialis allograft. Tantalum markers were injected into the graft, fixation devices, and bones. On the day of surgery and at 1, 2, 3, and 4 months, Roentgen stereophotogrammetric analysis was used to compute anterior laxity at 150 N of anterior force and the total slippage from both sites of fixation. A simple linear regression was performed to determine whether the millimeter-for-millimeter relation existed and a springs-in-series model of the graft construct was used to determine the extent to which the increase in stiffness caused by biological healing of the graft to the bone tunnel offset the increase in anterior laxity resulting from lengthening at the sites of fixation. There was no correlation between lengthening at the sites of fixation and the increase in anterior laxity at 1 month (R(2)=0.0, slope=0.2). Also, the increase in stiffness of the graft construct caused by biologic healing of the graft to the bone tunnel offset 0.7 mm of the 1.5 mm potential increase in anterior laxity resulting from lengthening at the sites of fixation. This relatively large offset of nearly 50% occurred because lengthening at the sites of fixation was small.

An in vivo study of the effect of distal femoral resection on passive knee extension.

A previous study showed that 1 mm of distal femoral resection restored knee extension 4.5°. We determined the relationship with a more accurate measurement technique. Twenty-six subjects treated with total knee arthroplasty were studied. Digital photographs of the extended knee with and without 1.5 and 3.0 mm thick augments placed between the femoral component and distal femur were analyzed, and knee extension was measured. One millimeter of distal femoral resection restored 1.8° of extension that is less correction than the previous study reported. Because an attempt to correct a 10° extension deficit by resecting the distal femur could require 5 mm or more of bone removal that moves the joint line too proximal, we recommend exploring other techniques before resecting the femur.

Surgical versus percutaneous multivessel coronary revascularization in patients with chronic kidney disease.

OBJECTIVES: This study compared contemporary outcomes following surgical versus percutaneous coronary revascularization for multivessel coronary artery disease (MVCAD) in patients with chronic kidney disease. METHODS: Patients with MVCAD and a reduced glomerular filtration rate (<60 ml/min) undergoing coronary bypass surgery (CABG) or percutaneous coronary intervention (PCI) at a single institution between 2010 and 2017 were included. The primary outcome was major adverse cardiac and cerebrovascular events (MACCE) defined as a composite outcome of death, stroke, myocardial infarction or repeat revascularization. Multivariable Cox regression models were used for risk-adjustment and propensity matching was also performed. RESULTS: A total of 1853 patients were included in the study (1269 CABG, 584 PCI). CABG was associated with greater 5-year freedom from MACCE (70.1% vs 47.3%, P < 0.0001), a finding that persisted after risk-adjustment. The rates of early and late mortality and readmission were also lower with CABG as were individual rates of myocardial infarction and repeat revascularization. A propensity-matched analysis generated 704 well-matched patients (352 in each arm) with similar results, including greater 5-year freedom from MACCE (72.8% vs 45.8%, P < 0.0001), improved 5-year survival (73.9% vs 52.3%, P < 0.0001), lower readmission (cause-specific hazard ratio 0.68, 95% confidence interval 0.58-0.80; P < 0.0001), lower individual rates of myocardial infarction (2.6% vs 9.7%, P < 0.0001) and repeat revascularization (1.1% vs 7.4%, P < 0.0001). CONCLUSIONS: CABG is associated with a lower MACCE rate than that of PCI in patients with MVCAD and chronic kidney disease. Multidisciplinary discussions regarding the optimal revascularization strategy are important in MVCAD, particularly in more complex scenarios such as chronic kidney disease.

Strategies for drug-eluting stent treatment of bifurcation coronary artery disease in the United States: insights from the e-Cypher S.T.L.L.R.trial.

OBJECTIVES: Our goal is to report the first large multicenter data for percutaneous coronary intervention (PCI) of bifurcation disease with drug-eluting stents (DES) in the United States. BACKGROUND: Bifurcation PCI remains a challenge to this date. There are limited data on outcomes of patients treated with bifurcation DES implantation, particularly in the United States. METHODS: There were 161 patients with bifurcation disease [side branch (SB) >or=2-mm] treated with >or=1 sirolimus-eluting stents at 41 centers participating in the Stent deployment Techniques on cLinicaL outcomes of patients treated with the cypheRstent (STLLR) trial. There was no protocol mandated strategy for bifurcation PCI. One-year outcome data were collected. Angiographic and clinical data were adjudicated independently. RESULTS: There were 147 patients (91.3%) treated with single stent strategy. Only 14 (8.7%) patients received sirolimus-eluting stents implantation in both branches. Among patients with single stent strategy, double wire strategy (DW) was selected in 27 (18.4%) patients whereas single wire strategy (SW) was selected in 120 (81.6%) patients. There were 48 (32.7%) Medina 1,1,1 bifurcations treated with SW (n = 34; 70.8%) and DW (n = 14; 29.2%). There were 26 procedures started with SW which had SB dilatation during the procedure, one as a bailout (TIMI-1 grade flow in the SB). Overall 1-year death, myocardial infarction, and target lesion revascularization occurred in 2.4, 4.0, and 5.6%, respectively. There was no significant difference in clinical outcomes between SW and DW. SB dilatation was associated with a high rate of stent thrombosis (8.6%). CONCLUSIONS: Main branch stenting without SB protection is the most common approach utilized in the STLLR study, which may reflect contemporary DES bifurcation strategies in the Unite States. This strategy was associated with an acceptable low incidence of adverse outcomes at 1-year.

Impact of Chronic Kidney Disease and Anemia on Outcomes After Percutaneous Coronary Revascularization.

Few studies have evaluated outcomes after percutaneous coronary intervention (PCI) in patients with both anemia (hemoglobin < 12 g/dl in women; <13 in men) and chronic kidney disease (CKD, estimated glomerular filtration rate < 60 ml/min/1.73 m2). Patients with coronary artery disease who underwent PCI in our health system from 2010 to 2018 were included (n = 10,756), excluding those with ST-elevation myocardial infarction or shock. We evaluated the individual and combined effects of anemia and CKD on outcomes. Five-year mortality was highest in the cohort with both anemia and CKD and lowest in those with neither. After multivariate analysis, with the group with neither anemia nor CKD as a reference, the adjusted hazard ratio for mortality was 1.68 (95% confidence interval [CI] 1.45 to 1.95, p <0.001) for those with anemia alone, 1.33 (95% CI 1.15 to 1.53, p <0.001) for those with CKD alone, and 2.83 (95% CI 2.49 to 3.22, p <0.001) for those with both anemia and CKD. With respect to readmission and reintervention, similar tends were observed, with patients with both CKD and anemia having the highest risk for these outcomes. In conclusion, the combined effects of anemia and CKD on outcomes post-PCI appear to be worse than either of their effects individually.

Coronary Bypass Versus Percutaneous Revascularization in Multivessel Coronary Artery Disease.

BACKGROUND: This study focused on contemporary outcomes after coronary artery bypass graft (CABG) surgery versus percutaneous coronary intervention (PCI) in patients with multivessel coronary artery disease (MVCAD). METHODS: This was a propensity-matched retrospective, observational analysis. Patients with MVCAD who underwent CABG or PCI between 2010 and 2018 and for whom data were available through the National Cardiovascular Data Registry or The Society of Thoracic Surgeons Adult Cardiac Surgery Database were included. The primary outcome was overall survival. Secondary outcomes included freedom from inpatient readmission and freedom from repeat revascularization. RESULTS: Of the initial 6,163 patients with MVCAD, the propensity-matched cohort included 844 in each group. The estimated 1-year mortality was 11.5% and 7.2% (p < 0.001) in the PCI and CABG groups, respectively, with an overall hazard ratio for mortality of PCI versus CABG of 1.64 (95% confidence interval [CI], 1.29 to 2.10; p < 0.001). The overall hazard ratio for readmission for PCI versus CABG was 1.42 (95% CI, 1.23 to 1.64; p < 0.001). The overall hazard ratio for repeat revascularization for PCI versus CABG was 4.06 (95% CI, 2.39 to 6.91; p < 0.001). Overall major adverse cardiovascular events and individual outcomes of mortality, readmission, and repeat revascularization all favored CABG across virtually all major clinical subgroups. CONCLUSIONS: This contemporary propensity-matched analysis of patients undergoing coronary revascularization for MVCAD demonstrates a significant mortality benefit with CABG over PCI, and this benefit is consistent across virtually all major patient subgroups. Futures studies are needed reflecting routine practice to assess how best to approach shared decision making and informed consent when it comes to revascularization decisions in any patient with MVCAD.

Clinicopathologic and molecular spectrum of RNASEH1-related mitochondrial disease.

OBJECTIVE: Pathologic ribonuclease H1 (RNase H1) causes aberrant mitochondrial DNA (mtDNA) segregation and is associated with multiple mtDNA deletions. We aimed to determine the prevalence of RNase H1 gene (RNASEH1) mutations among patients with mitochondrial disease and establish clinically meaningful genotype-phenotype correlations. METHODS: RNASEH1 was analyzed in patients with (1) multiple deletions/depletion of muscle mtDNA and (2) mendelian progressive external ophthalmoplegia (PEO) with neuropathologic evidence of mitochondrial dysfunction, but no detectable multiple deletions/depletion of muscle mtDNA. Clinicopathologic and molecular evaluation of the newly identified and previously reported patients harboring RNASEH1 mutations was subsequently undertaken. RESULTS: Pathogenic c.424G>A p.Val142Ile RNASEH1 mutations were detected in 3 pedigrees among the 74 probands screened. Given that all 3 families had Indian ancestry, RNASEH1 genetic analysis was undertaken in 50 additional Indian probands with variable clinical presentations associated with multiple mtDNA deletions, but no further RNASEH1 mutations were confirmed. RNASEH1-related mitochondrial disease was characterized by PEO (100%), cerebellar ataxia (57%), and dysphagia (50%). The ataxia neuropathy spectrum phenotype was observed in 1 patient. Although the c.424G>A p.Val142Ile mutation underpins all reported RNASEH1-related mitochondrial disease, haplotype analysis suggested an independent origin, rather than a founder event, for the variant in our families. CONCLUSIONS: In our cohort, RNASEH1 mutations represent the fourth most common cause of adult mendelian PEO associated with multiple mtDNA deletions, following mutations in POLG, RRM2B, and TWNK. RNASEH1 genetic analysis should also be considered in all patients with POLG-negative ataxia neuropathy spectrum. The pathophysiologic mechanisms by which the c.424G>A p.Val142Ile mutation impairs human RNase H1 warrant further investigation.

Regulation of desmocollin gene expression in the epidermis: CCAAT/enhancer-binding proteins modulate early and late events in keratinocyte differentiation.

Desmocollins (Dscs) are desmosomal cadherins that exhibit differentiation-specific patterns of expression in the epidermis. Dsc3 expression is strongest in basal cell layers, whereas Dsc1 is largely confined to upper, terminally differentiating strata. To understand better the processes by which Dsc expression is regulated in the epidermis, we have isolated Dsc3 and Dsc1 5'-flanking DNAs and analysed their activity in primary keratinocytes. In the present study, we found that transcription factors of the CCAAT/enhancer-binding protein family play a role in the regulation of expression of both Dscs and, in so doing, implicate this class of transcription factors in both early and late events in keratinocyte differentiation. We show that Dscs are differentially regulated by C/EBP (CCAAT/enhancer-binding protein) family members, with Dsc3 expression being activated by C/EBPbeta but not C/EBPalpha, and the reverse being the case for Dsc1. Expression of both Dscs is activated by another family member, C/EBPdelta. These results show for the first time how desmosomal cadherin gene expression is regulated and provide a mechanism for the control of other differentiation-specific genes in the epidermis.