Background: Sanger sequencing is a technology used to identify the gene sequence variants causing rare genetic disorders. However, designing and implementing a proficiency scheme for Sanger sequencing-based genetic testing is challenging because many molecular diagnostic laboratories are running sequencing tests for tens to hundreds of target genes. As such, we aimed to design and implement a method-based proficiency testing (PT) method for Sanger sequencing and to assess its feasibility in Korea. Methods: A pathogenic low density lipoprotein receptor (LDLR) variant was chosen as the positive PT material, and material without an LDLR variant was used as the negative PT material. We distributed the two PT materials with primer pair sets to 17 molecular diagnostic laboratories nationwide.We calculated the correct results (%) for variation type, zygosity, nucleotide change, amino acid change, variant classification, and clinical interpretation. Results: Fourteen laboratories responded to the survey. The results for the two PT materials were 100% correct for all evaluation points including variant type, zygosity, nucleotide change, amino acid change, variant classification, and clinical interpretation. Conclusions This pilot PT survey demonstrates a feasibility of using method-based PT for assessing the Sanger sequencing performance of molecular diagnostic laboratories in Korea.

Background: Sanger sequencing is a technology used to identify the gene sequence variants causing rare genetic disorders. However, designing and implementing a proficiency scheme for Sanger sequencing-based genetic testing is challenging because many molecular diagnostic laboratories are running sequencing tests for tens to hundreds of target genes. As such, we aimed to design and implement a method-based proficiency testing (PT) method for Sanger sequencing and to assess its feasibility in Korea. Methods: A pathogenic low density lipoprotein receptor (LDLR) variant was chosen as the positive PT material, and material without an LDLR variant was used as the negative PT material. We distributed the two PT materials with primer pair sets to 17 molecular diagnostic laboratories nationwide.We calculated the correct results (%) for variation type, zygosity, nucleotide change, amino acid change, variant classification, and clinical interpretation. Results: Fourteen laboratories responded to the survey. The results for the two PT materials were 100% correct for all evaluation points including variant type, zygosity, nucleotide change, amino acid change, variant classification, and clinical interpretation. Conclusions This pilot PT survey demonstrates a feasibility of using method-based PT for assessing the Sanger sequencing performance of molecular diagnostic laboratories in Korea.

Background and Objectives: Outcomes of deferring percutaneous coronary intervention (PCI) without invasive physiologic assessment for intermediate coronary lesions is uncertain.We sought to compare long-term outcomes between medical treatment and PCI of intermediate lesions without invasive physiologic assessment. Methods: A total of 899 patients with intermediate coronary lesions between 50% and 70% diameter-stenosis were randomized to the conservative group (n=449) or the aggressive group (n=450). For intermediate lesions, PCI was performed in the aggressive group, but was deferred in the conservative group. The primary endpoint was major adverse cardiac events (MACE, a composite of all-cause death, myocardial infarction [MI], or ischemia-driven any revascularization) at 3 years. Results: The number of treated lesions per patient was 0.8±0.9 in the conservative group and 1.7±0.9 in the aggressive group (p=0.001). At 3 years, the conservative group had a significantly higher incidence of MACE than the aggressive group (13.8% vs. 9.3%; hazard ratio [HR], 1.49; 95% confidence interval [CI], 1.00–2.21; p=0.049), mainly driven by revascularization of target intermediate lesion (6.5% vs. 1.1%; HR, 5.69; 95% CI, 2.20–14.73;p<0.001). Between 1 and 3 years after the index procedure, compared to the aggressive group, the conservative group had significantly higher incidence of cardiac death or MI (3.2% vs.0.7%; HR, 4.34; 95% CI, 1.24–15.22; p=0.022) and ischemia-driven any revascularization. Conclusions For intermediate lesions, medical therapy alone, guided only by angiography, was associated with a higher risk of MACE at 3 years compared with performing PCI, mainly due to increased revascularization.

Background: Sanger sequencing is a technology used to identify the gene sequence variants causing rare genetic disorders. However, designing and implementing a proficiency scheme for Sanger sequencing-based genetic testing is challenging because many molecular diagnostic laboratories are running sequencing tests for tens to hundreds of target genes. As such, we aimed to design and implement a method-based proficiency testing (PT) method for Sanger sequencing and to assess its feasibility in Korea. Methods: A pathogenic low density lipoprotein receptor (LDLR) variant was chosen as the positive PT material, and material without an LDLR variant was used as the negative PT material. We distributed the two PT materials with primer pair sets to 17 molecular diagnostic laboratories nationwide.We calculated the correct results (%) for variation type, zygosity, nucleotide change, amino acid change, variant classification, and clinical interpretation. Results: Fourteen laboratories responded to the survey. The results for the two PT materials were 100% correct for all evaluation points including variant type, zygosity, nucleotide change, amino acid change, variant classification, and clinical interpretation. Conclusions This pilot PT survey demonstrates a feasibility of using method-based PT for assessing the Sanger sequencing performance of molecular diagnostic laboratories in Korea.

Background: Sanger sequencing is a technology used to identify the gene sequence variants causing rare genetic disorders. However, designing and implementing a proficiency scheme for Sanger sequencing-based genetic testing is challenging because many molecular diagnostic laboratories are running sequencing tests for tens to hundreds of target genes. As such, we aimed to design and implement a method-based proficiency testing (PT) method for Sanger sequencing and to assess its feasibility in Korea. Methods: A pathogenic low density lipoprotein receptor (LDLR) variant was chosen as the positive PT material, and material without an LDLR variant was used as the negative PT material. We distributed the two PT materials with primer pair sets to 17 molecular diagnostic laboratories nationwide.We calculated the correct results (%) for variation type, zygosity, nucleotide change, amino acid change, variant classification, and clinical interpretation. Results: Fourteen laboratories responded to the survey. The results for the two PT materials were 100% correct for all evaluation points including variant type, zygosity, nucleotide change, amino acid change, variant classification, and clinical interpretation. Conclusions This pilot PT survey demonstrates a feasibility of using method-based PT for assessing the Sanger sequencing performance of molecular diagnostic laboratories in Korea.

Background and Objectives: Outcomes of deferring percutaneous coronary intervention (PCI) without invasive physiologic assessment for intermediate coronary lesions is uncertain.We sought to compare long-term outcomes between medical treatment and PCI of intermediate lesions without invasive physiologic assessment. Methods: A total of 899 patients with intermediate coronary lesions between 50% and 70% diameter-stenosis were randomized to the conservative group (n=449) or the aggressive group (n=450). For intermediate lesions, PCI was performed in the aggressive group, but was deferred in the conservative group. The primary endpoint was major adverse cardiac events (MACE, a composite of all-cause death, myocardial infarction [MI], or ischemia-driven any revascularization) at 3 years. Results: The number of treated lesions per patient was 0.8±0.9 in the conservative group and 1.7±0.9 in the aggressive group (p=0.001). At 3 years, the conservative group had a significantly higher incidence of MACE than the aggressive group (13.8% vs. 9.3%; hazard ratio [HR], 1.49; 95% confidence interval [CI], 1.00–2.21; p=0.049), mainly driven by revascularization of target intermediate lesion (6.5% vs. 1.1%; HR, 5.69; 95% CI, 2.20–14.73;p<0.001). Between 1 and 3 years after the index procedure, compared to the aggressive group, the conservative group had significantly higher incidence of cardiac death or MI (3.2% vs.0.7%; HR, 4.34; 95% CI, 1.24–15.22; p=0.022) and ischemia-driven any revascularization. Conclusions For intermediate lesions, medical therapy alone, guided only by angiography, was associated with a higher risk of MACE at 3 years compared with performing PCI, mainly due to increased revascularization.

Background: Sanger sequencing is a technology used to identify the gene sequence variants causing rare genetic disorders. However, designing and implementing a proficiency scheme for Sanger sequencing-based genetic testing is challenging because many molecular diagnostic laboratories are running sequencing tests for tens to hundreds of target genes. As such, we aimed to design and implement a method-based proficiency testing (PT) method for Sanger sequencing and to assess its feasibility in Korea. Methods: A pathogenic low density lipoprotein receptor (LDLR) variant was chosen as the positive PT material, and material without an LDLR variant was used as the negative PT material. We distributed the two PT materials with primer pair sets to 17 molecular diagnostic laboratories nationwide.We calculated the correct results (%) for variation type, zygosity, nucleotide change, amino acid change, variant classification, and clinical interpretation. Results: Fourteen laboratories responded to the survey. The results for the two PT materials were 100% correct for all evaluation points including variant type, zygosity, nucleotide change, amino acid change, variant classification, and clinical interpretation. Conclusions This pilot PT survey demonstrates a feasibility of using method-based PT for assessing the Sanger sequencing performance of molecular diagnostic laboratories in Korea.

Background and Objectives: Outcomes of deferring percutaneous coronary intervention (PCI) without invasive physiologic assessment for intermediate coronary lesions is uncertain.We sought to compare long-term outcomes between medical treatment and PCI of intermediate lesions without invasive physiologic assessment. Methods: A total of 899 patients with intermediate coronary lesions between 50% and 70% diameter-stenosis were randomized to the conservative group (n=449) or the aggressive group (n=450). For intermediate lesions, PCI was performed in the aggressive group, but was deferred in the conservative group. The primary endpoint was major adverse cardiac events (MACE, a composite of all-cause death, myocardial infarction [MI], or ischemia-driven any revascularization) at 3 years. Results: The number of treated lesions per patient was 0.8±0.9 in the conservative group and 1.7±0.9 in the aggressive group (p=0.001). At 3 years, the conservative group had a significantly higher incidence of MACE than the aggressive group (13.8% vs. 9.3%; hazard ratio [HR], 1.49; 95% confidence interval [CI], 1.00–2.21; p=0.049), mainly driven by revascularization of target intermediate lesion (6.5% vs. 1.1%; HR, 5.69; 95% CI, 2.20–14.73;p<0.001). Between 1 and 3 years after the index procedure, compared to the aggressive group, the conservative group had significantly higher incidence of cardiac death or MI (3.2% vs.0.7%; HR, 4.34; 95% CI, 1.24–15.22; p=0.022) and ischemia-driven any revascularization. Conclusions For intermediate lesions, medical therapy alone, guided only by angiography, was associated with a higher risk of MACE at 3 years compared with performing PCI, mainly due to increased revascularization.

Background and Objectives: Outcomes of deferring percutaneous coronary intervention (PCI) without invasive physiologic assessment for intermediate coronary lesions is uncertain.We sought to compare long-term outcomes between medical treatment and PCI of intermediate lesions without invasive physiologic assessment. Methods: A total of 899 patients with intermediate coronary lesions between 50% and 70% diameter-stenosis were randomized to the conservative group (n=449) or the aggressive group (n=450). For intermediate lesions, PCI was performed in the aggressive group, but was deferred in the conservative group. The primary endpoint was major adverse cardiac events (MACE, a composite of all-cause death, myocardial infarction [MI], or ischemia-driven any revascularization) at 3 years. Results: The number of treated lesions per patient was 0.8±0.9 in the conservative group and 1.7±0.9 in the aggressive group (p=0.001). At 3 years, the conservative group had a significantly higher incidence of MACE than the aggressive group (13.8% vs. 9.3%; hazard ratio [HR], 1.49; 95% confidence interval [CI], 1.00–2.21; p=0.049), mainly driven by revascularization of target intermediate lesion (6.5% vs. 1.1%; HR, 5.69; 95% CI, 2.20–14.73;p<0.001). Between 1 and 3 years after the index procedure, compared to the aggressive group, the conservative group had significantly higher incidence of cardiac death or MI (3.2% vs.0.7%; HR, 4.34; 95% CI, 1.24–15.22; p=0.022) and ischemia-driven any revascularization. Conclusions For intermediate lesions, medical therapy alone, guided only by angiography, was associated with a higher risk of MACE at 3 years compared with performing PCI, mainly due to increased revascularization.

Background: The benefits of transradial access (TRA) over transfemoral access (TFA) for bifurcation percutaneous coronary intervention (PCI) are uncertain because of the limited availability of device selection. This study aimed to compare the procedural differences and the in-hospital and long-term outcomes of TRA and TFA for bifurcation PCI using secondgeneration drug-eluting stents (DESs). Methods: Based on data from the Coronary Bifurcation Stenting Registry III, a retrospective registry of 2,648 patients undergoing bifurcation PCI with second-generation DES from 21 centers in South Korea, patients were categorized into the TRA group (n = 1,507) or the TFA group (n = 1,141). After propensity score matching (PSM), procedural differences, in-hospital outcomes, and device-oriented composite outcomes (DOCOs; a composite of cardiac death, target vessel-related myocardial infarction, and target lesion revascularization) were compared between the two groups (772 matched patients each group). Results: Despite well-balanced baseline clinical and lesion characteristics after PSM, the use of the two-stent strategy (14.2% vs. 23.7%, P = 0.001) and the incidence of in-hospital adverse outcomes, primarily driven by access site complications (2.2% vs. 4.4%, P = 0.015), were significantly lower in the TRA group than in the TFA group. At the 5-year follow-up, the incidence of DOCOs was similar between the groups (6.3% vs. 7.1%, P = 0.639). Conclusion The findings suggested that TRA may be safer than TFA for bifurcation PCI using second-generation DESs. Despite differences in treatment strategy, TRA was associated with similar long-term clinical outcomes as those of TFA. Therefore, TRA might be the preferred access for bifurcation PCI using second-generation DES.