A machine learning-based approach to directly compare the diagnostic accuracy of myocardial perfusion imaging by conventional and cadmium-zinc telluride SPECT.

BACKGROUND: We evaluated the performance of conventional (C) single-photon emission computed tomography (SPECT) and cadmium-zinc-telluride (CZT)-SPECT in a large cohort of patients with suspected or known coronary artery disease (CAD) and compared the diagnostic accuracy of the two systems using machine learning (ML) algorithms. METHODS AND RESULTS: A total of 517 consecutive patients underwent stress myocardial perfusion imaging (MPI) by both C-SPECT and CZT-SPECT. In the overall population, an excellent correlation between stress MPI data and left ventricular (LV) functional parameters measured by C-SPECT and by CZT-SPECT was observed (all P < .001). ML analysis performed through the implementation of random forest (RF) and k-nearest neighbors (NN) algorithms proved that CZT-SPECT has greater accuracy than C-SPECT in detecting CAD. For both algorithms, the sensitivity of CZT-SPECT (96% for RF and 60% for k-NN) was greater than that of C-SPECT (88% for RF and 53% for k-NN). CONCLUSIONS: MPI data and LV functional parameters obtained by CZT-SPECT are highly reproducible and provide good correlation with those obtained by C-SPECT. ML approach showed that the accuracy and sensitivity of CZT-SPECT is greater than C-SPECT in detecting CAD.

Effect of changes in perfusion defect size during serial stress myocardial perfusion imaging on cardiovascular outcomes in patients treated with primary percutaneous coronary intervention after myocardial infarction.

BACKGROUND: We evaluated the prognostic value of changes in perfusion defect size (PDS) on serial MPS in patients treated with primary percutaneous coronary intervention (PCI) after acute myocardial infarction (AMI). METHODS: We enrolled 112 patients treated with primary PCI after AMI who underwent two stress MPS within 1 month and after 6 months. Improvement in PDS was defined as a reduction ≥5%. Remodeling was defined as an increase in left ventricular (LV) end-diastolic volume index ≥20%. Cardiac events included cardiac death, nonfatal MI, unstable angina, repeated revascularization, and heart failure. RESULTS: During a median follow-up of 86 months, 22 events occurred. Event rate was higher (P < .01) in patients with worsening of PDS compared to those with unchanged or improved PDS. Moreover, patients with remodeling had a higher (P < .001) event rate compared to those without. At Cox analysis, worsening of PDS and remodeling resulted independent predictors of events (both P < .01). Patients with both worsening of PDS and remodeling had the worst event-free survival (P <.001). CONCLUSION: In patients treated with primary PCI after AMI, worsening of PDS and remodeling are associated to higher risk of events at long-term follow-up. Gated stress MPS improves risk stratification in these patients.

Comparing the Prognostic Value of Stress Myocardial Perfusion Imaging by Conventional and Cadmium-Zinc Telluride Single-Photon Emission Computed Tomography through a Machine Learning Approach.

We compared the prognostic value of myocardial perfusion imaging (MPI) by conventional- (C-) single-photon emission computed tomography (SPECT) and cadmium-zinc-telluride- (CZT-) SPECT in a cohort of patients with suspected or known coronary artery disease (CAD) using machine learning (ML) algorithms. A total of 453 consecutive patients underwent stress MPI by both C-SPECT and CZT-SPECT. The outcome was a composite end point of all-cause death, cardiac death, nonfatal myocardial infarction, or coronary revascularization procedures whichever occurred first. ML analysis performed through the implementation of random forest (RF) and k-nearest neighbors (KNN) algorithms proved that CZT-SPECT has greater accuracy than C-SPECT in detecting CAD. For both algorithms, the sensitivity of CZT-SPECT (96% for RF and 60% for KNN) was greater than that of C-SPECT (88% for RF and 53% for KNN). A preliminary univariate analysis was performed through Mann-Whitney tests separately on the features of each camera in order to understand which ones could distinguish patients who will experience an adverse event from those who will not. Then, a machine learning analysis was performed by using Matlab (v. 2019b). Tree, KNN, support vector machine (SVM), Naïve Bayes, and RF were implemented twice: first, the analysis was performed on the as-is dataset; then, since the dataset was imbalanced (patients experiencing an adverse event were lower than the others), the analysis was performed again after balancing the classes through the Synthetic Minority Oversampling Technique. According to KNN and SVM with and without balancing the classes, the accuracy (p value = 0.02 and p value = 0.01) and recall (p value = 0.001 and p value = 0.03) of the CZT-SPECT were greater than those obtained by C-SPECT in a statistically significant way. ML approach showed that although the prognostic value of stress MPI by C-SPECT and CZT-SPECT is comparable, CZT-SPECT seems to have higher accuracy and recall.

Quantification of myocardial perfusion reserve by CZT-SPECT: A head to head comparison with 82Rubidium PET imaging.

BACKGROUND: We measured myocardial blood flow (MBF) and perfusion reserve (MPR) by dynamic CZT-SPECT and 82Rb-PET in patients with suspected or known coronary artery disease (CAD) and compared the accuracy of the two methods in predicting obstructive CAD. METHODS: Twenty-five patients with available coronary angiography data underwent 99mTc-sestamibi CZT-SPECT and 82Rb-PET cardiac imaging. Stress and rest MBF and MPR were calculated by both methods and compared. Diagnostic accuracies of CZT-SPECT and PET were also assessed using a receiver-operator-characteristic curve. RESULTS: CZT-SPECT yielded similar baseline MBF, but higher hyperemic MBF and MPR values compared to PET. There was a modest correlation between the two methods for MPR (r = 0.56, P < .01). MPR by CZT-SPECT showed a good ability in identify a reduced MPR by PET, with an area under the curve of 0.85. A MPR cut-off of 2.5 was identified by CZT-SPECT for detection of abnormal MPR by PET, with a sensitivity, specificity and accuracy of 86%, 73% and 80%. The area under the curve for the identification of obstructive CAD by regional MPR were 0.83 for CZT-SPECT and 0.84 for PET (P = .90). At CZT-SPECT, a regional MPR of 2.1 provided the best trade-off between sensitivity and specificity for identifying obstructive CAD. Diagnostic accuracy of CZT-SPECT and PET using respective cut-off values was comparable (P = .62). CONCLUSION: Hyperemic MBF and MPR values obtained by CZT-SPECT are higher than those measured by 82Rb-PET imaging, with a moderate correlation between the two methods. CZT-SPECT shows good diagnostic accuracy for the identification of obstructive CAD. These findings may encourage the use of this new technique to a better risk stratification and patient management.

Pretest models for predicting abnormal stress single-photon emission computed tomography myocardial perfusion imaging.

BACKGROUND: The frequency of abnormal stress SPECT myocardial perfusion imaging (MPS) decreased over the past decades despite an increase in the prevalence of cardiovascular risk factors. These findings strengthen the need to develop more effective strategies for appropriately referring patients with suspected coronary artery disease (CAD) to cardiac imaging. The aim of this study was to develop pretest assessment models for predicting abnormal stress MPS. METHODS: We included 5,601 consecutive patients with suspected CAD, who underwent stress MPS at our academic center. Two different models were considered: a basic model including age, gender, and anginal symptoms; and a clinical model including also diabetes, hypertension, hypercholesterolemia, smoking, and family history of CAD. RESULTS: In patients with abnormal MPS, the basic model classified more than 75% of patients as intermediate risk, whereas only 23% were incorrectly classified as low risk. In patients with normal MPS, 45% were correctly classified as low risk and none as high risk. Basic and clinical models had a limited discriminating capacity (area under the receiver operating characteristic curve 0.644 for basic model and 0.647 for clinical model) between individuals with and without abnormal stress MPS. The decision curve analysis demonstrates a high net benefit across a range of threshold probabilities from ~ 15% to ~30% for both models. CONCLUSIONS: A pretest risk stratification based on traditional cardiovascular risk factors has a limited value for predicting an abnormal stress MPS in patients with suspected CAD. However, selecting a proper threshold probability enhances the appropriateness of referral to stress MPS.

Added prognostic value of left ventricular shape by gated SPECT imaging in patients with suspected coronary artery disease and normal myocardial perfusion.

BACKGROUND: Left ventricular (LV) remodeling is associated with adverse cardiovascular events. We evaluated the added prognostic value of LV shape index (SI) assessed by gated single-photon emission tomography (SPECT) in patients without known coronary artery disease (CAD). METHODS AND RESULTS: We studied 674 patients with normal myocardial perfusion and normal LV ejection fraction (EF) on stress gated SPECT imaging. An automated software program was used to calculate end-diastolic and end-systolic LVSI. An LVSI ≤ 0.54 at end-systole was considered normal. Follow-up was 96% complete with a median follow-up of 37 months. During follow-up, 25 events occurred (3.8% cumulative event rate). Event-free survival was lower in patients with abnormal end-systolic LVSI (P < .001). Age (P = .021), diabetes (P = .048), and end-systolic LVSI (P < .001) were independent predictors of events. LVSI added prognostic information increasing the global chi-square of the model including age and diabetes from 15.15 to 25.97 (P < .001). The effect of diabetes on hazard ratio increased with increasing values of end-systolic LVSI. The probability of events at 48 months predicted by Weibull analysis progressively increased with increasing values of end-systolic LVSI and was higher in patients with diabetes as compared to those without. Decision curve analyses indicate that the model including end-systolic LVSI resulted in an increased net benefit between 5% and 30% threshold probability, indicating superior estimation of outcomes at low threshold probability levels. CONCLUSIONS: The evaluation of LVSI may identify patients with early-stage LV remodeling and at higher risk of adverse cardiac events, even in the presence of normal myocardial perfusion.

Exploring the clinical validity of borderline personality disorder components.

Borderline personality disorder (BPD) is recognized as a complex syndrome, resulting in a heterogeneous diagnostic category. Besides the characteristics of the disorder itself, comorbid disorders play an important role in this complexity. The aim of the study is to analyze the clinical validity of 3 components for BPD Diagnostic and Statistical Manual of Mental Disorders criteria--called affective dysregulation, behavioral dysregulation, and disturbed relatedness--investigating differences in patterns of comorbidity. For this purpose, 365 patients with suspected BPD were included in the study. To test our hypothesis, patients were classified into 5 clusters using a K-cluster analysis to study the clinical validity of the 3 components based on the 3-factor model of BPD. Differences in comorbidity, previous suicide attempts, and self-harm behaviors among the defined clusters were analyzed. Between-cluster differences were observed for Axis I and Axis II disorders as well as in the frequency of suicide attempts and in self-harm behaviors. The study of BPD based on the 3 components seems to be more useful than the study of BPD as a unitary construct to help further our understanding of this complex disorder. In the present study, the 3 BPD components have allowed us to analyze the complex comorbidity of BPD patients. This solution could be considered an interesting way to clarify BPD etiology, diagnosis, and treatment efficacy.

The SCID-II and DIB-R interviews: Diagnostic association with poor outcome risk factors in Borderline Personality Disorder / Entrevistas SCID-II y DIB-R: asociación del diagnóstico de Trastorno Límite de la Personalidad con factores de riesgo de mal pronóstico

This study assesses whether patients diagnosed with Borderline Personality Disorder (BPD) according to the Structured Clinical Interview for DSM-IV Axis II Disorders (SCID-II) or the Revised Diagnostic Interview for Borderlines (DIB-R) present differences in factors associated with risk of poor outcome. Three hundred fifty-two patients were evaluated with SCID-II and DIB-R. Patients diagnosed as BPD according to one or both instruments were compared in BPD poor outcome risk factors. The analysis was conducted on the participants who were assigned to SCID-II (n = 135) and SCID-II/DIB-R (n = 126) groups. The group diagnosed with BPD according the combined SCID-II/DIB-R interview showed a significantly greater association with risk of poor outcome predictors, such as total number of comorbid Axis II disorders, number of BPD criteria, presence of comorbid paranoid personality disorder, and worse occupational status. No differences between groups were found in the affective instability BPD criterion, self-reported impulsivity, post-traumatic stress disorder, major depressive disorder or presence of any cluster C comorbidity. The observed differences were large enough to advise caution in generalizing findings from studies without considering what measurement was used for the BPD diagnosis (AU)

En el presente estudio se compara si existen diferencias en factores relacionados con mal pronóstico en pacientes diagnosticados de Trastorno Límite de Personalidad (TLP) en función de si cumplían los criterios diagnósticos para el trastorno según la Entrevista Clínica Estructurada para los Trastornos de Personalidad del Eje II del DSM-IV (SCID-II) o la Entrevista Diagnóstica para el Trastorno Límite - revisada (DIB-R). Se evaluó una muestra de 352 pacientes mediante la SCID-II y la DIB-R. Tras el proceso de evaluación, dos grupos fueron comparados: el grupo SCID-II (n= 135) y el grupo SCID-II/DIB-R (n= 126). Comparado con el grupo SCID-II, el grupo SCID-II/DIB-R presentó de forma significativa más predictores de mala evolución, concretamente número total de trastornos comórbidos del Eje II, número de criterios TLP, presencia de trastorno paranoide de la personalidad comórbido y peor situación laboral. No se observaron diferencias significativas en inestabilidad afectiva, impulsividad autoinformada, trastorno por estrés postraumático, trastorno depresivo mayor o trastornos de personalidad del Cluster C comórbidos. Las diferencias observadas fueron lo suficientemente importantes como para recomendar precaución al generalizar los resultados de aquellos estudios que utilizan uno de los instrumentos a los que usan el otro (AU)

The SCID-II and DIB-R interviews: diagnostic association with poor outcome risk factors in Borderline Personality Disorder.

This study assesses whether patients diagnosed with Borderline Personality Disorder (BPD) according to the Structured Clinical Interview for DSM-IV Axis II Disorders (SCID-II) or the Revised Diagnostic Interview for Borderlines (DIB-R) present differences in factors associated with risk of poor outcome. Three hundred fifty-two patients were evaluated with SCID-II and DIB-R. Patients diagnosed as BPD according to one or both instruments were compared in BPD poor outcome risk factors. The analysis was conducted on the participants who were assigned to SCID-II (n = 135) and SCID-II/DIB-R (n = 126) groups. The group diagnosed with BPD according the combined SCID-II/DIB-R interview showed a significantly greater association with risk of poor outcome predictors, such as total number of comorbid Axis II disorders, number of BPD criteria, presence of comorbid paranoid personality disorder, and worse occupational status. No differences between groups were found in the affective instability BPD criterion, self-reported impulsivity, post-traumatic stress disorder, major depressive disorder or presence of any cluster C comorbidity. The observed differences were large enough to advise caution in generalizing findings from studies without considering what measurement was used for the BPD diagnosis.

Effectiveness of combined individual and group dialectical behavior therapy compared to only individual dialectical behavior therapy: a preliminary study.

Dialectical behavior therapy (DBT) is an effective therapy. However, treating borderline personality disorder (BPD) patients with standard DBT can be problematic in some institutions due to logistical or cost limitations. The aim of this preliminary study is to examine the efficacy of Individual DBT in 37 BPD patients, compared with Combined individual/Group DBT in 14 BPD patients. Outcome measures included suicide attempts, self-harm behaviors, and visits to emergency departments. These variables were examined at pretreatment, 12 months/end of treatment, and at an 18-month follow-up. In addition, dropout rates were examined. Significant improvements on the outcome measures were observed across both versions of DBT treatment, particularly at the 18-month follow-up assessment. No significant differences were observed between Individual DBT and Combined individual/Group DBT on any of the posttreatment evaluations. An individual version of DBT may be an effective and less costly option for BPD treatment. Larger controlled trials are needed to confirm the results.

Borderline Personality Disorder (BPD) diagnosis with the self-report Personality Diagnostic Questionnaire­4+(PDQ-4+): confirmation of the 3-factor structure.

INTRODUCTION: The clinical heterogeneity and elevated comorbidity of Borderline Personality Disorder (BPD) have suggested the possible existence of several factors or subtypes of this construct. Studies published to date mainly show that this diagnosis could be represented either as a 1-dimensional model or 3-factor model. However, most of the studies have analyzed the factorial structure of the BPD DSM-IV criteria only using semi-structured interviews. This study has aimed to analyze the factorial structure of BPD DSM-IV criteria used in the self-report PDQ-4+. METHOD: A total of 159 psychiatric outpatients with suspicion of BPD diagnosis were evaluated. Confirmatory Factor Analyses (CFA) was performed for BPD criteria in PDQ-4+ and two previously defined structures were examined and compared: a 1-dimensional model and a 3-factor model. RESULTS: Both models showed good fit indexes. However, the results of the CFA showed better goodness of fit indexes (χ(2)/gl; CFI; RMSEA; TLI; AIC and GFI) for the 3-factor model. CONCLUSIONS: BPD is a construct that can be used to describe three factors of criteria that represent different features of this disorder. The three factors, which could be called Disturbed Relatedness, Affective Instability and Behavioral Dyscontrol, can also be explained by the combination of different diagnostic criteria. The existence of these factors could indicate the presence of different subgroups of BPD patients with different clinical patterns.

Avaliação do índice de fraturas das limas ProTaper(r) em canais simulados / Evaluation of rate of fractures in ProTaper(r) files in simulated canais

Resumo Introdução - O presente estudo tem como objetivo avaliar o comportamento no que se refere à fratura das limas ProTaper(r) em relação ao número de vezes em que as mesmas foram utilizadas na instrumentação de canais simulados em blocos de resina. Métodos - Seis especialistas em Endodontia participaram do trabalho. Cada operador recebeu dois jogos de limas ProTaperg que seriam reutilizadas até que ocorresse a fratura de alguma lima e a instrurnentação seria interrompida. Resultados e Conclusões - Através da análise dos resultados concluiu-se que: 1. O uso das limas ProTaper(r) em canais curvos mostrou- se mais seguro até o quarto uso, 2. Existe uma tendência da fratura ocorrer no ponto de maior angulação da curvatura. 3. Quando não há interferências cervicais, as limas que mais fraturam são as de maiores conicidades, as "F".(au)

Relationship of good and poor Wisconsin Card Sorting Test performance to illness duration in schizophrenia: a cross-sectional analysis.

The authors investigated whether schizophrenic patients with good and poor performance on the Wisconsin Card Sorting Test (WCST) showed cognitive modifications related to duration of illness. Of the 154 patients evaluated with the WCST, 56 subjects had normal or mildly impaired performance and 98 showed impairment on the basis of the number of categories achieved (0-3 categories = poor performance). These subsamples were then cross-sectionally divided into three subsamples depending on length of illness (< 5 years, 6-10 years, > 10 years). The inclusion of 69 healthy controls allowed the effect of age to be taken into account. The schizophrenic group as a whole and the group of poor performers did not show differences in any of the WCST indices related to length of illness. Good performers instead showed improvement on the intermediate length-of-illness group (6-10 years of illness), and then decline in the third one (> 10 years). Good performers only showed a positive significant correlation between age, age at onset, educational level and successful WCST performance. Results for the poor performers support the hypothesis of no progressive 'deteriorating' course of schizophrenia, while good performers show an unstable pattern of cognitive functions. These data support the hypothesis that cognitive deficits associated with schizophrenia cannot be considered a unitary trait, but emerge along different hypothetical trajectories.