Age and outcomes following personalized antiplatelet therapy in chronic coronary syndrome patients: a post hoc analysis of the randomized PATH-PCI trial

It is particularly important to establish more effective and safer antiplatelet treatment strategies according to age. The present subanalysis of the PATH-PCI trial was to determine the safety and efficacy of any dual-antiplatelet therapy (DAPT) strategy in different age groups. We randomized 2285 chronic coronary syndrome (CCS) patients undergoing percutaneous coronary intervention (PCI) into a standard group or a personalized group from December 2016 to February 2018. The personalized group received personalized antiplatelet therapy (PAT) based on a novel platelet function test (PFT). The standard group received standard antiplatelet therapy (SAT). Then, all patients were divided according to age (under the age of 65 years and aged 65 years or over) to investigate the association and interaction of age on clinical outcomes at 180 days. In the patients under the age of 65 years, the incidence of NACEs was decreased in the personalized group compared to the standard group (5.1% vs. 8.8%, HR: 0.603, 95% CI: 0.409-0.888, P = .010). The rates of MACCEs (3.3% vs. 7.7%, HR: 0.450, 95% CI: 0.285-0.712, P = .001), MACEs (2.2% vs. 5.4%, HR: 0.423, 95% CI: 0.243-0.738, P = .002) also decreased. We did not find a significant difference in bleeding between the groups. In the patients aged 65 years or over, no difference in the primary endpoint was found (4.9% vs. 4.2%, P = .702), and comparable rates of survival were observed with the two strategies (all Ps > 0.05). The present study shows that PAT according to PFT was comparable to SAT at the 180-day follow-up for both ischemic and bleeding endpoints in CCS patients aged 65 years or over who underwent PCI. In patients under the age of 65 years, PAT can reduce ischemic events but does not increase bleeding, and it is an effective and safe treatment strategy. It may be necessary for young CCS patients after PCI to undergo PAT early after PCI.

Effectiveness of lipid-lowering therapy on mortality and major adverse cardiovascular event outcomes in patients undergoing percutaneous coronary intervention: a network meta-analysis of randomised controlled trials

BACKGROUND

Emergency percutaneous coronary intervention (PCI) can quickly restore myocardial perfusion after acute coronary syndrome. Whether and which lipid-lowering regimens are effective in reducing major adverse cardiovascular events (MACEs) and mortality risk after PCI remain unclear.

OBJECTIVE

This study assessed the benefits of different lipid-lowering regimens on the risk of MACEs and mortality in the post-PCI population by network meta-analysis.

METHODS

Public databases, including PubMed, Embase and the Cochrane Library, were searched from inception to August 2022. Randomised controlled trials (RCTs) on lipid-lowering regimens in post-PCI populations were included and analysed. The outcomes were the incidence of all-cause mortality and MACEs, whether reported as dichotomous variables or as HRs.

RESULTS

Thirty-nine RCTs were included. For MACEs, alirocumab plus rosuvastatin (OR: 0.18; 95% CI: 0.07 to 0.44), evolocumab plus ezetimibe and statins (OR: 0.19; 95% CI: 0.06 to 0.59), eicosapentaenoic acid (EPA) plus pitavastatin (HR: 0.67; 95% CI: 0.49 to 0.96) and icosapent ethyl plus statins (HR: 0.73; 95% CI: 0.62 to 0.86) had significant advantages and relatively high rankings. For mortality, rosuvastatin (OR: 0.30; 95% CI: 0.11 to 0.84), ezetimibe plus statins (OR: 0.55; 95% CI: 0.43 to 0.89) and icosapent ethyl plus statins (OR: 0.66; 95% CI: 0.45 to 0.96) had significant advantages compared with the control.

CONCLUSION

EPA, especially icosapent ethyl, plus statins had a beneficial effect on reducing the risk of MACEs and mortality in post-PCI patients. Proprotein convertase subtilisin/kexin type-9 inhibitors plus statins were able to reduce the risk of MACEs, but the risk of mortality remained unclear.

PROSPERO REGISTRATION NUMBER

CRD42018099600.

The Fibrinogen-to-Albumin Ratio Is Associated with Poor Prognosis in Patients with Coronary Artery Disease: Findings from a Large Cohort

We aimed to evaluate the association of the fibrinogen-to-albumin ratio (FAR) with the clinical outcomes of coronary artery disease (CAD). All 14,944 patients with CAD evaluated in the present study were from a prospective cohort that recruited 15,250 patients admitted in the First Affiliated Hospital of Xinjiang Medical University between December 2016 and October 2021. The all-cause mortality (ACM) and cardiac mortality (CM) were selected as the primary endpoints. The secondary endpoints were major adverse cardiovascular events (MACEs), major adverse cardiac and cerebrovascular events (MACCEs), and non-fatal myocardial infarction (NFMI). The optimal FAR cutoff value was determined by using a receiver operating characteristic (ROC) curve analysis. Using 0.1 as the cutoff value, all the patients were divided into two groups: a low-FAR group (FAR < 0.1, n = 10,076) and a high-FAR group (FAR ≥ 0.1, n = 4918). The incidence of outcomes between the two groups was compared. The high-FAR group exhibited a higher incidence of ACM (5.3% vs. 1.9%), CM (3.9% vs. 1.4%), MACEs (9.8% vs. 6.7%), MACCEs (10.4% vs. 7.6%), and NFMI (2.3% vs. 1.3%) than the low-FAR group. To adjust the confounders, multivariate Cox regression analyses showed that the risk in the high-FAR group was increased 2.182 fold in ACM (HR = 2.182, 95% CI: 1.761 ~ 2.704, P < 0.001), 2.116 fold in CM (HR = 2.116, 95% CI: 1.761 ~ 2.704, P < 0.001), 1.327 fold in MACEs (HR = 1.327, 95% CI: 1.166 ~ 1.510, P < 0.001), 1.280 fold in MACCEs (HR = 1.280, 95% CI: 1.131 ~ 1.448, P < 0.001), and 1.791 fold in NFMI (HR = 1.791, 95% CI:1.331 ~ 2.411, P < 0.001), compared to the low-FAR group. The present study suggested that the high-FAR group was an independent and powerful predictor of adverse outcomes in CAD patients.

The higher the serum albumin, the better? Findings from the PRACTICE study

AIMS

The relation between hypoalbuminemia and coronary artery disease (CAD) has been established. However, the association of increased albumin level and outcomes of CAD has not been investigated.

METHODS

There were 14 994 CAD patients from the PRACTICE study, which is a large, single center prospective cohort study based on case records and follow-up registry performed in the First Affiliated Hospital of Xinjiang Medical University from Dec. 2016 to Oct. 2021 in the present study. All the 14 994 patients were divided into five categories according albumin levels: <35 g/L group (n = 1 478), 35-40 g/L group (n = 5 007), 40-45 g/L group (n = 6 076), 45-50 g/L group (n = 1 835), and ≥50 g/L group (n = 598).

RESULTS

A total of 448 all-cause deaths(ACD), 333 cardiac deaths (CD), 1 162 MACEs and 1 276 MACCEs were recorded during up to 60-months follow-up period. After adjusting for confounders, we observed a non-linear relation for either MACE or MACCE with the lowest risk at 45 g/L of albumin levels. A threshold value of albumin ≥50 g/L was associated with an increased risk for either MACE (adjusted HR=1.617, 95%CI:1.130-2.315, P = 0.009) or MACCE (adjusted HR= 1.439, 95%CI: 1.007-2.056, P = 0.045) in multivariable Cox regression model. For mortality, we only found decreased (<35 g/L) but not increased albumin level was associated with either ACD (HR=2.744, 95%CI: 1.631-4.617, P<0.001) or CD (HR=2.736, 95%CI: 1.484-5.045, P = 0.001).

CONCLUSIONS

In the present study, a U-shaped curve relation was identified between albumin levels and MACE and MACCE in CAD patients, with the lowest risk at 45 g/L levels.

Mutated CYP17A1 promotes atherosclerosis and early-onset coronary artery disease

BACKGROUND

Coronary artery disease (CAD) is a multi-factor complex trait and is heritable, especially in early-onset families. However, the genetic factors affecting the susceptibility of early-onset CAD are not fully characterized.

METHODS

In the present study, we identified a rare nonsense variant in the CYP17A1 gene from a Chinese Han family with CAD. To validate the effect of this variation on atherosclerosis and early-onset coronary artery disease, we conducted studies on population, cells, and mice.

RESULTS

The mutation precisely congregated with the clinical syndrome in all the affected family members and was absent in unaffected family members and unrelated controls. Similar to the human phenotype, the CYP17A1-deficient mice present the phenotype of metabolic syndrome with hypertension, increased serum glucose concentration, and presentation of central obesity and fatty liver. Furthermore, CYP17A1 knockout mice or CYP17A1 + ApoE double knockout mice developed more atherosclerotic lesions than wild type (WT) with high fat diary. In cell models, CYP17A1 was found to be involved in glucose metabolism by increasing glucose intake and utilization, through activating IGF1/mTOR/HIF1-α signaling way, which was consistent in CYP17A1 knockout mice with impaired glucose tolerance and insulin resistance.

CONCLUSIONS

Through our study of cells, mice and humans, we identified CYP17A1 as a key protein participating in the pathophysiology of the atherosclerotic process and the possible mechanism of CYP17A1 C987X mutation induced atherosclerosis and early-onset CAD involving glucose homeostasis regulation was revealed. Video Abstract.

Low HDL Cholesterol Associated with Reduced Bleeding Risk in Patients Who Underwent PCI: Findings from the PRACTICE Study

AIMS

We sought to examine the dose-response relationship between high-density lipoprotein cholesterol(HDL-C) and bleeds in coronary artery disease(CAD) patients who underwent percutaneous coronary intervention(PCI) .

METHODS

All the 15 250 participants were from the Personalized Antiplatelet Therapy According to CYP2C19 Genotype in Coronary Artery Disease(PRACTICE) study, which is a large, single centre prospective cohort study based on case records and follow-up registry performed in the First Affiliated Hospital of Xinjiang Medical University from Dec. 2016 to Oct. 2021. We divided all the patients into five groups according HDL-C levels:≤35mg/dL group(n=4732), 35-45 mg/dL group (n=6049), 45-55 mg/dL group (n=2826), 55-65 mg/dL group (n=1117), >65 mg/dL group (n=526). The incidence of bleeds, mortality, ischaemic events and net adverse clinical events among the five groups was compared.

RESULTS

A total of 713 major bleeds, 1180 ischemic events, 456 deaths and 1893 net adverse clinical events were recorded during up to 60-months follow-up period. After adjusting for confounders, we observed a non-linear relation for major bleeds, with the highest risk at intermediate HDL-C levels(45-55mg/dL). We also identified a dose-response relationship for ischaemic events. A threshold value of HDL-C≤35 mg/dL(adjusted HR=0.627, 95%CI: 0.494-0.798, P<0.001) was associated with a decreased risk for major bleeds in multivariable Cox regression model. The results were consistent in multiple sensitivity analyses and propensity matching(PSM) anslysis.

CONCLUSIONS

In the present study, a non-linear association was identified between HDL-C levels and major bleeds in CAD patients who underwent PCI, with the higher risk at intermediate levels. However, further multicenter studies are warranted.

Decreased free fatty acid levels associated with adverse clinical outcomes in coronary artery disease patients with type 2 diabetes: Findings from the PRACTICE study

BACKGROUND AND AIMS

Increased free fatty acid (FFA) levels are known to be strongly associated with mortality in coronary artery disease (CAD) patients and the development of type 2 diabetes (T2DM). However, few studies have been large enough to accurately examine the relationship between FFA levels and mortality in CAD patients with T2DM.

METHODS

From December 2016 to October 2021, 10 395 CAD patients enrolled in PRACTICE, a prospective cohort study in China, were divided into four groups according to baseline FFA concentration. We investigated mortality, including all-cause mortality (ACM) and cardiac mortality (CM), as the primary endpoint. The secondary endpoints were major adverse cardiovascular and cerebrovascular events (MACCEs) and major adverse cardiovascular events (MACEs). The median follow-up time was 24 months.

RESULTS

In the total cohort, there were 222 ACMs, 164 CMs, 718 MACEs and 803 MACCEs were recorded. After controlling for baseline variables, the association between FFA levels and the risk of mortality presented a nonlinear U-shaped curve, with the lowest risk at 310 µmol/L. We also identified a nonlinear U-shaped relationship for ischemic events (MACE or MACCE) with the lowest risk at 500 µmol/L. Subgroup analysis showed that a U-shaped relationship between FFA and mortality or ischemic events was observed only in individuals with T2DM but not in nondiabetic CAD patients.

CONCLUSIONS

A nonlinear U-shaped association was identified between baseline FFA levels and mortality or ischemic events in CAD patients with T2DM.

Age-Bilirubin-International Normalized Ratio (INR)-Creatinine (ABIC) Score, a Potential Prognostic Model for Long-Term Mortality of CAD Patients After PCI

Background

Given that age, international normalized ratio (INR), total bilirubin, and creatinine are reported to be independent risk factors for predicting outcome in patients with coronary artery disease (CAD), it is possible that the age-bilirubin-INR-creatinine (ABIC) score might be a potential prognostic model for patients with CAD.

Methods

A total of 6046 CAD patients after percutaneous coronary intervention (PCI) from the retrospective cohort study (Identifier: ChiCTR-ORC-16010153) were evaluated finally. The primary outcome long-term mortality and secondary endpoints mainly major adverse cardiovascular and cerebrovascular events (MACCEs) were recorded. Multivariate Cox regression models were used to determine risk factors for mortality and MACCEs.

Results

The ABIC score was significantly higher in the death group than in the survival group. After adjusting for other CAD risk factors, the ABIC score was identified to be an independent risk factor for long-term mortality by multivariate Cox analysis. When in the high ABIC group, the incidence of all-cause mortality would increased 1.7 times (adjusted HR=1.729 (1.347-2.218), P<0.001), and 1.5 times for cardiac death (adjusted HR=1.482 (1.126-1.951), P=0.005).

Conclusion

The present study indicated that ABIC score≥7.985 predicts high long-term mortality and cardiac death risk for PCI patients. The ABIC score might be a potential prognostic model for patients with PCI.

ALB-dNLR Score Predicts Mortality in Coronary Artery Disease Patients After Percutaneous Coronary Intervention

Background

The influence of the albumin/derived neutrophil and lymphocyte ratio (ALB-dNLR) on the outcomes of patients with coronary artery disease (CAD) after percutaneous coronary intervention (PCI) is not known. Here, we aimed to determine the association between the ALB-dNLR score and post-PCI CAD patient outcomes.

Methods

A total of 6,050 patients from the First Affiliated Hospital of Xinjiang Medical University were enrolled between January 2008 and December 2016. These patients were divided into three groups according to their ALB-dNLR scores (0 points, n = 1,121; 1 point, n = 3,119; 2 points, n = 1,810). Mortality after PCI [all-cause (ACM) and cardiac (CM)] was taken as the primary endpoint. The prognostic value of the ALB-dNLR score was determined with the Cox proportional hazard model after adjustment for covariates.

Results

The ACM and CM rates differed among participants in the three groups (P = 0.007 and P = 0.034, respectively). Multivariate Cox analysis showed that the ALB-dNLR score independently predicted both ACM [1 point vs. 0 points, HR = 1.249 (95% CI: 0.79–1.774), P = 0.215; 2 points vs. 0 points, HR = 1.777 (95% CI: 1.239–2.549), P = 0.002] and CM [1 point vs. 0 points, HR = 1.294 (95% CI: 0.871–1.922), P = 0.202; 2 points vs. 0 points, HR = 1.782 (95% CI: 1.185–1.782), P = 0.027]. We also found that among male patients in the three groups, both ACM and CM rates differed (P = 0.006 and P = 0.017, respectively). Multivariate Cox analysis showed that the ALB-dNLR score independently predicted both ACM [1 point vs. 0 points, HR = 1.237 (95% CI: 0.806–0.330), P = 0.330; 2 points vs. 0 points, HR = 1.790 (95% CI: 1.159–2.764), P = 0.009] and CM [1 point vs. 0 points HR = 1.472 (95% CI: 0.892–2.430), P = 0.130; 2 points vs. 0 points, HR = 1.792 (95% CI: 1.182–3.289), P = 0.009].

Conclusion

The ALB-dNLR score is a credible predictor for mortality in patients with CAD who have undergone PCI.

Hemoglobin-to-Red-Cell Distribution Width Ratio Is a Novel Predictor of Long-Term Patient Outcomes After Percutaneous Coronary Intervention: A Retrospective Cohort Study

Background

The hemoglobin level and red cell distribution width (RDW) have been linked to the prognosis of coronary atherosclerotic heart disease (CAHD). However, the relationship between the ratio of hemoglobin to the RDW (HRR) and clinical outcomes after percutaneous coronary intervention (PCI) is not known. Here, we explored the impact of the HRR on clinical outcomes after PCI.

Methods

In our study, we selected 6,046 CAHD patients with PCI hospitalized in the First Affiliated Hospital of Xinjiang Medical University from 2008 to 2016. The patients were grouped according to their HRR ratio: group A (HRR < 10.25, n = 2,344) and group B (HRR ≥ 10.25, n = 3,702). The difference in clinical outcomes between the two groups was compared. Patients were followed up for 35.9 ± 22.6 months.

Results

Three hundred nine patients died during follow-up. These included 166 patients (7.1%) in the HRR < 10.25 group and 143 patients (3.9%) in the HRR ≥ 10.25 group (P < 0.001). The incidences of cardiogenic death (5.7 vs. 3.2%) and major cardiovascular adverse events (16.5 vs. 12.9%) also differed significantly between the groups (both Ps < 0.001). Analysis using the multivariate Cox proportional hazard model found a significant association between a decreased HRR and post-PCI mortality (all-cause death, adjusted HR: 1.479, 95% CI: 1.156–1.893, p = 0.002; cardiac death, adjusted HR: 1.470, 95% CI: 1.116–1.936, p = 0.006).

Conclusion

The HRR is predictive of post-PCI mortality among CAHD patients.

Characteristics of the Intestinal Microorganisms in Middle-Aged and Elderly Patients: Effects of Smoking

Introduction: Smoking affects the occurrence and development of many diseases. We attempt to study the structure of intestinal flora in the middle-aged and elderly population as well as how smoking affects the intestinal flora. Methods: We collected population information, biochemical indicators, and patient feces from 188 middle-aged and elderly male patients, and their feces were tested for the 16S rRNA gene of intestinal flora. Results: We performed a cluster analysis on the intestinal structure of the included population and found that there was a significant difference in the number of smokers between each group (p = 0.011). Subsequently, the microbiological diversity analysis of current smokers and nonsmokers was carried out. The results indicated that there was a significant difference in species composition between the two groups (p = 0.029). Through the analysis on LEfSe differential bacteria, it was found that in current smoking patients, the abundances of the genus Bifidobacterium and the genus Coprobacillus were less, while the abundances of the genera Shigella, Paraprevotella, Burkholderia, Sutterella, Megamonas, and p-75-a5 under the family level of Erysipelotrichaceae were slightly high. We analyzed the correlation between the abundances of these eight different bacteria and clinical indicators. The results revealed the following: the abundance of the genus Bifidobacterium was negatively correlated with fasting blood glucose (r = -0.198, p = 0.006) and positively correlated with uric acid (r = 0.207, p = 0.004) and total bilirubin (r = 0.175, p = 0.017); Shigella bacteria were positively correlated with fasting blood glucose (r = 0.160, p = 0.028) and uric acid (r = 0.153, p = 0.036) levels; the genus Paraprevotella and BMI (r = -0.172, p = 0.018) are negatively correlated; the abundance of the genus Burkholderia was positively correlated with γ-glutamyltransferase (r = 0.146, p = 0.045) levels; Sutterella was correlated with fasting blood glucose (r = 0.143, p = 0.05) and creatinine level (r = -0.16, p = 0.027), which was positively correlated with fasting blood glucose and negatively correlated with creatinine. Conclusions: In middle-aged and elderly patients with cardiovascular disease, smoking can reduce the abundance of Bifidobacterium, while the abundances of some negative bacteria such as Burkholderia, Sutterella, and Megamonas increase.

Diabetes and Outcomes Following Personalized Antiplatelet Therapy in Coronary Artery Disease Patients Who Have Undergone PCI

CONTEXT

A personalized antiplatelet therapy guided by a novel platelet function testing (PFT), PL-12, is considered an optimized treatment strategy in stable coronary artery disease (CAD) patients undergoing percutaneous coronary intervention (PCI). However, the safety and efficacy of any dual-antiplatelet therapy (DAPT) strategy may differ in relation to diabetes status.

OBJECTIVE

The aim of this study was to compare the outcomes of PFT-guided personalized DAPT in stable CAD patients with and without diabetes mellitus.

METHODS

The PATH-PCI trial randomly assigned 2285 stable CAD patients to either personalized antiplatelet therapy or standard antiplatelet treatment. We investigated the association and interaction of diabetes on clinical outcomes across 2 treatment groups.

RESULTS

We did not find a significant difference between the personalized group and the standard group in net adverse clinical events in either diabetes patients (10.3% vs 13.4%, P = .224) or in the nondiabetic group (3.1% vs 5.0%, P = .064). In diabetes patients (n = 646, 28.3%), the overall ischemic event rates were significantly low (6.8% vs 11.3%, HR = 0.586, 95% CI, 0.344-0.999, P = .049) and the bleeding event rates did not differ between the 2 groups (3.5% vs 3.3%, HR = 1.066, 95% CI, 0.462-2.458, P = .882). Similarly, in nondiabetic patients, the overall ischemic event rates were significantly low (1.8% vs 4.2%, HR = 0.428, 95% CI, 0.233-0.758, P = .006) and the bleeding event rates did not differ between the 2 groups (1.6% vs 0.9%, HR = 1.802, 95% CI: 0.719-4.516, P = .209).

CONCLUSION

The present study suggests that personalized antiplatelet therapy according to PFT can reduce ischemic events but not increase bleedings in stable CAD patients with or without diabetes who have undergone PCI.

Gut Microbiome-Based Diagnostic Model to Predict Diabetes Mellitus

The aim of this study was to determine the diversity of intestinal microflora and its correlation with clinical parameters in diabetic patients and healthy subjects and to assess the importance of intestinal flora in patients with diabetes. Forty-four patients with diabetes were included. The control group included 47 healthy people. Their data, biochemical indicators and results from 16S rRNA sequencing of their fecal samples were collected. Compared with the healthy population, the intestinal flora of the diabetic patients was obviously abnormal. Within the diabetes group, the abundances of the genera Faecalibacterium, Prevotella, and Roseburia were higher, and the abundances of the genera Shigella and Bifidobacterium were lower. In the correlation analysis between bacteria and clinical indicators, it was found that the genera Veillonella and unclassified_Enterobacteriaceae were negatively related to blood glucose, while the genera Phascolarctobacterium, unidentified_Bacteroidales and Prevotella were significantly positively correlated with fasting blood glucose. Twelve microbial markers were detected in the random forest model, and the area under the curve (AUC) was 84.1%. This index was greater than the diagnostic effect of fasting blood glucose. This was also supported by the joint diagnostic model of microorganisms and clinical indicators. In addition, the intestinal flora significantly improved the diagnosis of diabetes. In conclusion, it can be concluded from these results that intestinal flora is essential for the occurrence and development of diabetes, which seems to be as important as blood glucose itself.

Abbreviations: PCoA: principal coordinate analysis; NMDS: non econometric multidimensional scaling analysis; LEfSe: linear discriminant analysis effect size; LDA: linear discriminant analysis; POD: probability of disease; BMI: body mass index; DCA: decision curve analysis

Gut Microbiota Characterization in Patients with Asymptomatic Hyperuricemia: probiotics increased

Asymptomatic hyperuricemia (AH) is an early stage of gout. Emerging evidence shows that the intestinal microbiota is related to gout. However, the relationship between AH and the intestinal microbiota is poorly understood. Therefore, the aim of the current study was to explore the possible correlation between AH and intestinal flora. We compared the intestinal microbial communities of AH (45 cases) and healthy subjects (45 cases) by 16S rRNA gene sequencing and clustering analysis on the incorporated population. Intestinal-type clustering can be divided into two groups, and significant differences in the proportion of AH are found among different bowel types. Alpha diversity indices were higher in the AH group than in the control group, and beta diversity indices also showed significant differences. A total of 19 genera were found different between the AH group and the control group. Compared with the control group, some probiotics are increased in the AH population. Two groups were ranked by importance of bacteria. We found the different bacteria partially coincided with the important bacteria, and the joint diagnosis level of the important bacteria was good. Conclusion: There were significant differences in the composition of intestinal biota between AH patients and healthy subjects. Some probiotics increased in AH.

The Fibrinogen-to-Albumin Ratio Is Associated With Outcomes in Patients With Coronary Artery Disease Who Underwent Percutaneous Coronary Intervention

Coronary artery disease (CAD) is a systemic chronic inflammatory disease, and serum fibrinogen and albumin are 2 important factors in systemic inflammation. We aimed to investigate the relationship between the fibrinogen–albumin ratio (FAR) and outcomes in patients with CAD who underwent percutaneous coronary intervention (PCI). All patients were from the Clinical Outcomes and Risk Factors of Patients with Coronary Heart Disease after PCI (CORFCHD-PCI) study, which is a retrospective cohort study (Identifier: ChiCTR-ORC-16010153) that includes a total of 6050 patients with CAD after PCI from January 2008 to December 2016. A total of 5829 patients with CAD after PCI were recruited in the present study. They were divided into 2 groups according to the FAR cutoff value, which was calculated using a receiver operating characteristic curve, a low group (FAR < 0.095, n = 3811), and a high group (FAR ≥ 0.095, n = 2018). The average follow-up time was 35.9 ± 22.6 months. The multivariate Cox proportional hazards model showed that FAR was independently correlated with all-cause mortality (adjusted hazard ratio [HR] = 1.432 [1.134-1.808], P = .003), cardiac mortality (adjusted HR = 1.579 [1.218-2.047], P = .001), major adverse cardiac and cerebrovascular events (adjusted HR = 1.296 [1.125-1.494], P < .001), major adverse cardiac events (adjusted HR = 1.357 [1.170-1.572], P < .001), and heart failure (adjusted HR = 1.540 [1.135-2.091], P = .006). The present study indicated that the FAR was associated with adverse outcomes in patients with CAD who underwent PCI.

The STING-IRF3 pathway is involved in lipotoxic injury of pancreatic β cells in type 2 diabetes

Lipotoxic injury of pancreatic β cells is an important pathological feature in type 2 diabetes mellitus (T2DM). Stimulator of interferon genes (STING) can recognize its own DNA leaked into the cytoplasm from damaged mitochondria or nuclei of the host cell, thus activating its downstream factor interferon regulatory factor 3 (IRF3), causing inflammation and apoptosis. The STING-IRF3 signaling pathway is closely related to glycolipid metabolism, but its relationship with the lipotoxicity of pancreatic β cells has rarely been reported. Here, we investigated the role of the STING-IRF3 signaling pathway in lipotoxicity-induced inflammation, apoptosis, and dysfunction of pancreatic β cells. We examined the activation of STING and IRF3 in islets of db/db mice and identified the role of the STING-IRF3 signaling pathway in palmitic acid (PA)-induced lipotoxic injury of INS-1, a rat insulinoma cell line. STING and phosphorylated IRF3 including downstream interferon-β were upregulated in islets of db/db mice and PA-induced INS-1 cells. Gene silencing of STING or IRF3 ameliorated PA-induced INS-1 cell inflammation and apoptosis, and reversed impaired insulin synthesis. Additionally, PA induced downregulation of the phosphoinositide 3-kinase-AKT signaling pathway, and impaired high glucose-stimulated insulin secretion was reversed after knockdown of STING or IRF3. Our results suggest that activation of the STING-IRF3 pathway triggers inflammation and apoptosis of pancreatic β cells, leading to β-cell damage and dysfunction. Hence, inhibition of this signaling pathway may represent a novel approach for β-cell protection in T2DM.

Cardiac Shock Wave Therapy for Coronary Heart Disease: an Updated Meta-analysis

Introduction

The aim of this article is to study the efficacy and safety of cardiac shock wave therapy (CSWT) in the treatment of coronary heart disease (CAD).

Methods

A comprehensive search of electronic databases and a manual search of conference papers and abstracts were performed until September 30, 2018. The studies using RevMan 5.3 and STATA 14.0 softwares were reviewed, and meta-analyses were performed on 13 indicators, such as a six-min walking distance test (6MWT), New York Heart Association (NYHA) functional class, Seattle Angina Questionnaire (SAQ) score, angina class (Canadian Cardiology Society [CCS]), etc.

Results

A total of 26 articles were included. The total patient population was 855, of which 781 patients were treated with CSWT. Meta-analyses indicated that 6MWT (mean difference [MD] 75.64, 95% confidence interval [CI] 49.03, 102.25, P<0.00001) and NYHA (MD -0.70, 95% CI -0.92) in the CSWT group were comparable to those in the conventional revascularization group (MD -0.70, 95% CI -0.92, -0.49, P<0.00001). SAQ (MD 10.75, 95% CI 6.66, 14.83, P<0.00001), CCS (MD -0.99, 95% CI -1.13, -0.84, P<0.00001), nitrate dosage (MD -1.84, 95% CI -2.77, -1.12, P<0.00001), LVEF (MD 3.77, 95% CI 2.17, 5.37, P<0.00001), and SSS (MD -4.29, 95% CI -5.61, -2.96, P<0.00001), SRS (MD -2.90, 95% CI -4.85, -0.95, P=0.004), and the exercise test (standard mean difference 0.57, 95% CI 0.12, 1.02, P=0.01) all showed significant differences.

Conclusion

CSWT may offer beneficial effects to patients with CAD, but more large-scale clinical studies are needed to further verify its therapeutic effect.

Baseline white blood cell count-to-apolipoprotein A1 ratio as a novel predictor of long-term adverse outcomes in patients who underwent percutaneous coronary intervention: a retrospective cohort study

Background

Previous studies suggested that baseline white blood cell count and apolipoprotein A1 levels were associated with clinical outcomes in patients with coronary heart disease (CAD) who underwent percutaneous coronary intervention (PCI). However, the ratio of baseline white blood cell count-to-apolipoprotein A1 level (WAR) and CAD after PCI have not been investigated. The present study investigated the effects of baseline WAR on long-term outcomes after PCI in patients with CAD.

Methods

A total of 6050 patients with CAD who underwent PCI were included in the study. Of these, 372 patients were excluded because no baseline white blood cell counts or apolipoprotein A1 (ApoA1) data was available or because of malignancies or other diseases. Finally, 5678 patients were enrolled in the present study and were divided into 3 groups according to WAR value: lower group - WAR< 5.25 (n = 1889); median group - 5.25 ≤ WAR≤7.15 (n = 1892); and higher group - WAR≥7.15 (n = 1897). The primary endpoint was long-term mortality, including all-cause mortality (ACM) and cardiac mortality (CM), after PCI. The average follow-up time was 35.9 ± 22.6 months.

Results

A total of 293 patients developed ACM, including 85 (4.5%) patients in the lower group, 90 (4.8%) patients in the median group, and 118 (6.2%) patients in the higher group. The risk of ACM, cardiac mortality (CM), major adverse cardiovascular and cerebrovascular events (MACCEs), and major adverse cardiovascular events (MACEs) increased 62.6% (hazard risk [HR] =1.626, 95%CI: 1.214–2.179, P = 0.001), 45.5% (HR = 1.455, 95%CI: 1.051–2.014, P = 0.024), 21.2% (HR = 1.212, 95%CI: 1.011–1.454, P = 0.038), and 23.8% (HR = 1.238, 95%CI: 1.025–1.495, P = 0.027), respectively, as determined by multivariate Cox regression analyses comparing the patients in the higher group to patients in the lower group. Patients with a WAR≥4.635 had 92.3, 81.3, 58.1 and 58.2% increased risks of ACM, CM, MACCEs and MACEs, respectively, compared to the patients with WAR< 4.635. Every 1 unit increase in WAR was associated with 3.4, 3.2, 2.0 and 2.2% increased risks of ACM, CM, MACCEs and MACEs, respectively, at the 10-year follow-up.

Conclusion

The present study indicated that baseline WAR is a novel and an independent predictor of adverse long-term outcomes in CAD patients who underwent PCI.

Gamma-glutamyl transferase to albumin ratio as a novel predictor of bleeding events and mortality in patients after percutaneous coronary intervention: A retrospective cohort study

OBJECTIVES

To determine whether gamma-glutamyl transferase (GGT) to albumin ratio (GAR) independently predicts mortality and bleeding events in coronary artery disease (CAD) patients who undergo percutaneous coronary intervention (PCI).

BACKGROUND

Serum GGT and albumin levels have been associated with CAD risk and mortality. However, more analysis is needed to determine their predictive relationship with adverse outcomes.

METHODS

In total, 5,638 patients from a large retrospective cohort study were enrolled from January 2008 to December 2016 and divided into two groups (GAR <0.62, n = 2,712 and GAR ≥0.62, n = 2,926). The average follow-up time was 35.9 ± 22.6 months. Multivariate Cox regression analyses were performed to determine the risk of all-cause mortality and bleeding events associated with GAR.

RESULTS

The low-GAR group had a significantly higher number of all-cause mortality (p = .016) and bleeding events (p = .010) than the high-GAR group. Multivariate Cox regression analyses showed that the risk of all-cause death and bleeding events decreased by 23.8% (hazard risk [HR] = 0.762 95% confidence interval [CI]: 0.601-0.966, p = .025) and 39.4% (HR = 00.616, 95% CI: 0.446-0.852, p = .003), respectively, in the high-GAR group. In patients with acute coronary syndrome, the risk of bleeding events decreased by 57.3% in the high-GAR group (HR = 0.427, 95% CI: 0.234-0.781, p = .006). In patients with stable coronary heart disease, the risk of all-cause death decreased 28.6% (HR = 0.714, 95% CI: 0.540-0.944, p = .018) in the high-GAR group.

CONCLUSION

GAR was an independent and novel predictor of mortality and bleeding events in CAD patients who underwent PCI.

Personalized antiplatelet therapy guided by a novel detection of platelet aggregation function in stable coronary artery disease patients undergoing percutaneous coronary intervention: a randomized controlled clinical trial

Aims

A number of studies have attempted to demonstrate the benefits associated with personalized antiplatelet therapy guided by platelet function testing, which has led to disappointing findings. In this study, we used a new platelet function test to guide antiplatelet therapy in stable coronary artery disease (CAD) patients after percutaneous coronary intervention (PCI).

Methods and results

In the present randomized controlled trial, a total of 2237 patients with stable CAD undergoing PCI were randomly chosen to be administered personalized antiplatelet therapy (personalized group; n = 1123) or standard antiplatelet treatment (standard group; n = 1114). The patients in the standard therapy group, without detecting the platelet aggregation rate, were administered a 75 mg/day clopidogrel maintenance dosage plus 100 mg/day of aspirin for at least 6 months after the procedure. For the patients in the personalized therapy group, the antiplatelet strategy was performed according to the maximum aggregation rate (MAR), determined using a novel platelet analyser, PL-12. If MAR &gt; 55%, 90 mg ticagrelor was administered twice daily plus 100 mg/day of aspirin after PCI. If MAR ≤55%, 75 mg/day clopidogrel plus 100 mg/day of aspirin was administered after PCI. The primary endpoint was net clinical adverse events, which were a composite of cardiac death, myocardial infarction, stroke, stent thrombosis, urgent revascularization, and bleeding [Bleeding Academic Research Consortium (BARC) definitions, Type 2, 3, or 5], in the 180-day period after randomization. The primary endpoint was reached in 58 patients in the personalized group, compared with 85 patients in the standard group [5.1% vs. 7.5%, hazard ratio (HR) 0.678, 95% confidence interval (CI) 0.486–0.947, P = 0.023], on intention-to-treat analysis. We also found that the net clinical adverse events (including ischaemic and bleeding events) were significantly reduced in the personalized group at 30 days after PCI compared to the standard group (1.5% vs. 3.0%, HR 0.510, 95% CI 0.284–0.915, P = 0.020). We did not find a significant difference in major bleeding events at either the 30-day (0.5% vs. 0.3%, P = 0.322) or the 180-day follow-up (2.1% vs. 1.6%, P = 0.364) between the two groups.

Conclusion

The present study suggests that personalized antiplatelet therapy according to MAR can significantly improve the net clinical benefit 180 days after PCI.

Red blood cell distribution width as long-term prognostic markers in patients with coronary artery disease undergoing percutaneous coronary intervention

Background

The aim of this study was to assess the prognostic value of red blood cell distribution width (RDW) in patients with coronary artery disease undergoing percutaneous coronary intervention (PCI).

Methods

A retrospective cohort study (CORFCHD-PCI, [Identifier: ChiCTR-INR-16010153]) of 6050 patients who were hospitalized with a diagnosis of coronary artery disease (CAD) and treated with PCI from January 2008 to December 2016 were enrolled in the study. The primary outcome was long-term mortality after PCI. Clinical follow-up data of participating patients were obtained during an outpatient examination 35.9 ± 22.6 months after PCI. Demographic and clinical data and admission laboratory parameters were recorded, and patients were categorized into two groups according to RDW level (high group ≥13.1%; low group < 13.1%).

Results

Multivariate Cox regression analysis revealed RDW as an independent prognosis factor for cardiac death. The incidence of cardiac death increased 1.33 times in patients in the high RDW group (HR, 1.331; 95% CI, 1.009–1.755, P = 0.043). Kaplan–Meier survival analysis suggested that patients with high RDW tended to have an increased accumulated risk of cardiac death. However, we did not found significant differences in the incidence of long-term mortality (adjusted HR = 1.203[0.941–1.537], P = 0.140), MACCE (adjusted HR = 1.128[0.979–1.301], P = 0.096), MACE (adjusted HR = 1.155[0.994–1.341], P = 0.059), stroke, bleeding events or readmission between the two groups.

Conclusion

The baseline level of RDW is an independent predictor for cardiac death in post-PCI CAD patients.

Gamma-Glutamyl Transferase-to-Platelet Ratio as a Novel Predictor of Long-Term Adverse Outcomes in Patients after Undergoing Percutaneous Coronary Intervention: A Retrospective Cohort Study

BACKGROUND

 Gamma-glutamyl transferase (GGT) has been shown to be involved in the pathogenesis of both coronary artery disease (CAD) and liver disease, and it has been reported that the GGT-to-platelet ratio (GPR) is an independent predictor for adverse outcomes from liver fibrosis and hepatic carcinoma. However, the relation between the GPR and adverse outcomes in CAD patients after percutaneous coronary intervention (PCI) has not been investigated.

METHODS

 A total of 5,636 patients enrolled in Clinical Outcomes and Risk Factors of Patients with Coronary Heart Disease after PCI, a retrospective cohort study, from January 2008 to December 2016, were divided into two groups according to GPR (GPR < 0.12, n = 2,769 and GPR ≥ 0.12, n = 2,867). The primary outcome was long-term mortality including all-cause mortality (ACM) and cardiac mortality (CM) after PCI. The average follow-up time was 35.9 ± 22.6 months.

RESULTS

 We found that there were significant differences between the two groups in the incidences of ACM (p = 0.011), CM (p = 0.001), major adverse cardiovascular events (MACEs, p < 0.024), major adverse cardiovascular and cerebrovascular events (MACCEs, p = 0.014) and bleeding events (p = 0.003). Multivariate Cox regression analyses showed that GPR was an independent predictor for ACM (hazard ratio [HR]: 1.536 [95% confidence interval [CI]:1.162-2.032], p = 0.003), CM (HR: 1.763 [95% CI: 1.283-2.424], p < 0.001), MACCEs (HR: 1.269 [95% CI: 1.066-1.511], p = 0.007) and MACEs (HR: 1.308 [95% CI: 1.089-1.570], p = 0.004) in stable CAD patients but that it was an independent predictor for only the incidence of bleeding events (HR: 3.104 [95% CI: 1.680-5.736], p < 0.001) in acute coronary syndrome (ACS) patients.

CONCLUSION

 This study indicates that GPR is an independent and novel predictor of adverse long-term outcomes in CAD patients who underwent PCI.

Activation of the STING-IRF3 pathway promotes hepatocyte inflammation, apoptosis and induces metabolic disorders in nonalcoholic fatty liver disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a common result of obesity and metabolic syndrome. Hepatocyte injury and metabolic disorders are hallmarks of NAFLD. Stimulator of interferon genes (STING) and its downstream factor interferon regulatory factor 3 (IRF3) trigger inflammatory reaction in response to the presence of cytosolic DNA. STING has recently been shown to play an important role in early alcoholic liver disease. However, little is known about the role of STING-IRF3 pathway in hepatocyte injury. Here, we aimed to examine the effect of STING-IRF3 pathway on hepatocyte metabolism, inflammation and apoptosis.

METHODS

We examined the activation of the STING-IRF3 pathway, a high-fat diet (HFD)-induced obese mouse model, and determined the role of this pathway in a free fatty acid (FFA)-induced hepatocyte inflammatory response, injury, and dysfunction in L-O2 human liver cells.

RESULTS

STING and IRF3 were upregulated in livers of HFD-fed mice and in FFA-induced L-O2 cells. Knocking down either STING or IRF3 led to a significant reduction in FFA-induced hepatic inflammation and apoptosis, as evidenced by modulation of the nuclear factor κB (NF-κB) signaling pathway, inflammatory cytokines, and apoptotic signaling. Additionally, STING/IRF3 knockdown enhanced glycogen storage and alleviated lipid accumulation, which were found to be associated with increased expression of hepatic enzymes in glycolysis and lipid catabolism, and attenuated expression of hepatic enzymes in gluconeogenesis and lipid synthesis.

CONCLUSIONS

Our results suggest that the STING-IRF3 pathway promotes hepatocyte injury and dysfunction by inducing inflammation and apoptosis and by disturbing glucose and lipid metabolism. This pathway may be a novel therapeutic target for preventing NAFLD development and progression.

Genetic diversity analysis of tree peony germplasm using iPBS markers

We examined the genetic diversity of 10 wild species (populations) and 55 varieties of tree peony using inter-primer binding site (iPBS) markers. From a total of 36 iPBS primers, 16 were selected based on polymorphic amplification. The number of bands amplified by each primer ranged from 9 to 19, with an average of 12.88 bands per primer. The length of bands ranged from 100 to 2000 bp, concentrated at 200 to 1800 bp. Sixteen primers amplified 206 bands in total, of which 173 bands were polymorphic with a polymorphism ratio of 83.98%. Each primer amplified 10.81 polymorphic bands on average. The data were then used to construct a phylogenetic tree using unweighted pair group method with arithmetic mean methods. Clustering analysis showed that the genetic relationships among the varieties were not only related to the genetic background or geographic origin, but also to the flowering phase, flower color, and flower type. Our data also indicated that iPBS markers were useful tools for classifying tree peony germplasms and for tree peony breeding, and the specific bands were helpful for molecular identification of tree peony varieties.

Distribution of Staphylococcus species among human clinical specimens and emended description of Staphylococcus caprae

By DNA-DNA hybridization on microplates, we identified 1,230 strains of staphylococci from human clinical specimens and determined the distribution of species. The 10 Staphylococcus species isolated most often were S. epidermidis (31.3%), S. aureus (23.3%), S. haemolyticus (12.2%), S. caprae (10.7%), S. simulans (4.4%), S. hominis (4.0%), S. capitis (3.9%), S. saprophyticus (3.6%), S. warneri (2.2%), and S. lugdunensis (1.3%). From these results, we realized that S. caprae strains were widely distributed in human clinical specimens. The description in Bergey's Manual of Systematic Bacteriology indicates that no strains of S. caprae produce acid from fructose and mannitol, but all our S. caprae strains produced acid from fructose and mannitol. Consequently, many strains of S. caprae isolated from human clinical specimens have been misidentified as S. haemolyticus or S. hominis by conventional biochemical tests. In this paper, we propose an emended description of S. caprae.

Streptococcus peroris sp. nov. and Streptococcus infantis sp. nov., new members of the Streptococcus mitis group, isolated from human clinical specimens

Taxonomic studies were performed on eight strains of alpha-haemolytic streptococci that showed very low DNA-DNA hybridization similarity values with all established members of the mitis group of the genus Streptococcus. These strains were isolated from the tooth surface and pharynx of humans. 16S rRNA gene sequence analysis showed that these strains belonged to the mitis group, but that they fell into two new branches. DNA-DNA hybridization demonstrated two new similarity groups. From the results of the present study, the names Streptococcus peroris sp. nov. and Streptococcus infantis sp. nov. are proposed for these new groups. The type strains are O-66T (= GTC 848T = JCM 10158T) and O-122T (= GTC 849T = JCM 10157T), respectively.

Description of Arthrobacter creatinolyticus sp. nov., isolated from human urine

Three strains of creatinine-hydrolysing bacteria isolated from human urine were characterized taxonomically. They were aerobic, non-spore-forming, Gram-positive rods with the peptidoglycan of the cell wall containing lysine. MK-8 and MK-9 were found to be the major types of menaquinone. The G + C content of the DNA was 66-67 mol%. The 16S rRNA sequence of one strain (GIFU 12498) was determined and aligned with other high-G + C-content Gram-positive rods from different genera. Following phylogenetic analysis, this strain was placed in the genus Arthrobacter. Arthrobacter protophormiae was the most closely related species in the phylogenetic tree, and this species also showed the highest sequence homology value (97%) with GIFU 12498. However, DNA-DNA hybridization indicated that GIFU 12498 did not belong to A. protophormiae (33.8 +/- 3.5% chromosomal similarity). The three urine strains belonged to one species because they shared more than 95% DNA-DNA similarity. It is proposed that these strains are placed in the genus Arthrobacter as a new species, Arthrobacter creatinolyticus sp. nov. The type strain of A. creatinolyticus is GIFU 12498, which has been deposited in the Japan Collection of Microorganisms (JCM) with the accession number JCM 10102.

Determination of 23S rRNA sequences from members of the genus Streptococcus and characterization of genetically distinct organisms previously identified as members of the Streptococcus anginosus group

The 23S rRNA gene sequences of eight type strains of the genus Streptococcus were determined. Three species-specific probes for the three members of the Streptococcus anginosus group and one group-specific probe for these three species were designed. The PCR-amplified 23S rRNA gene sequences of 28 clinical strains were examined by hybridization with the four oligonucleotide probes. They were suspected to be members of the S. anginosus group by biochemical tests; however, only 21 strains (75%) hybridized to one of the three species probes. Seven biochemically atypical strains did not hybridize to these species-specific probes. Of the seven strains, three hybridized to the group-specific probe. The 23S ribosomal RNA sequences of these three strains differed by three bases within the 20-base probe area of S. anginosus. The phylogenetic tree of the 16S rRNA of these three strains located them within the branch of S. anginosus. The remaining four strains, which did not hybridize to group- or species-specific probes, had a raffinose-positive and VP-negative phenotype. The probe hybridization results showed that these four strains did not belong to the S. anginosus group and were closely related to S. parasanguis according to partial sequences of their 16S rRNA genes.

Genetic identification of members of the genus Corynebacterium at genus and species levels with 16S rDNA-targeted probes

16S rRNA gene-targeted probes were designed for the identification of corynebacteria at the genus and species levels. The genus-specific probe hybridized all clinically important members of the genus Corynebacterium and could distinguish them from other coryneform bacteria and phylogenetically related high G+C% gram-positive bacteria, including Actinomyces, Rhodococcus, Gordona, Nocardia, Streptomyces, Brevibacterium and Mycobacterium. The species-specific probes for C. jeikeium and C. diphtheriae could differentiated these two species from other members of this genus. The probes were used to select corynebacteria among gram-positive clinical isolates which had been tentatively identified as corynebacteria by biochemical tests. We screened 59 strains with the genus-specific probe; 51 strains hybridized to the genus-specific probe, 8 did not. Of the 51 strains that hybridized to the genus-specific probe, 1 hybridized to the C. diphtheriae species probe and 13 hybridized to the C. jeikeium species probe. The 8 strains that did not hybridize to the genus probe were further characterized by analyzing cell wall diaminopimelic acid and partial 16S rRNA sequencing. The results indicated that these strains were distributed in the genera Arthrobacter and Brevibacterium.

Transfer of Streptococcus adjacens and Streptococcus defectivus to Abiotrophia gen. nov. as Abiotrophia adiacens comb. nov. and Abiotrophia defectiva comb. nov., respectively

We performed this study to determine the 16S rRNA sequences of the type strains of Streptococcus adjacens and Streptococcus defectivus and to calculate the phylogenetic distances between these two nutritionally variant streptococci (NVS) and other members of the genus Streptococcus. S. adjacens and S. defectivus belonged to one cluster, but this cluster was not closely related to other streptococcal species. A comparative analysis of the sequences of these organisms and other low-G+C-content gram-positive bacteria revealed that the two NVS species formed a distinct cluster and were only remotely related to the Aerococcus and Carnobacterium clusters. The highest level of homology (93.7%) was found between S. adjacens and Carnobacterium divergens. Carnobacterium species have meso-diaminopimelic acid in their cell walls, but S. adjacens and S. defectivus have L-lysine as the diamino acid at position 3 in their peptidoglycan tetrapeptides. On the basis of our findings and the results of previous phenotypic studies, we propose that the NVS species should be placed in a new genus, the genus Abiotrophia, as Abiotrophia adiacens comb. nov. and Abiotrophia defectiva comb. nov.

Determination of 16S rRNA sequences of Streptococcus mitis and Streptococcus gordonii and phylogenetic relationships among members of the genus Streptococcus

We determined the 16S rRNA sequences of the type strains of Streptococcus mitis and Streptococcus gordonii and calculated the phylogenetic distances between those organisms and other members of the genus Streptococcus. The viridans group streptococci were separated into five phylogenetic groups; we named these groups the anginosus group, the mitis group, the salivarius group, the bovis group, and the mutans group. S. mitis and S. gordonii clustered in the mitis group together with Streptococcus pneumoniae, Streptococcus oralis, Streptococcus sanguis, and Streptococcus parasanguis at levels of sequence homology of more than 96%. Within this group, S. mitis, S. oralis, and S. pneumoniae exhibited more than 99% sequence homology with each other, although the DNA-DNA similarity values for their total chromosome DNAs were less than 60%.