275 research outputs found

    INVESTIGATING DRILL CONSTRAINT KINEMATICS IN MALE BASEBALL PITCHERS USING MARKERLESS MOTION CAPTURE

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    This study investigated the kinematic differences that pitching constraint drills elicit compared to a baseball pitch. 18 male baseball pitchers with average height (183.7 ± 5.2cm), weight (87.4 ± 9.6kg), and skill level (Professional (4), Collegiate (5), High School (9)) were included. Video was recorded using a single camera from the open side. Each pitcher threw 3 maximum effort pitches from a mound. Next, 3 maximum effort throws were recorded for 8 different throwing drills: medicine ball hook’em drill, pivot pickoff drill, foot-up rocker drill, walk-in drill, towel drill, janitor drill, drop-step drill, and long toss. Videos were processed using pitchAITM, a markerless motion capture solution. The medicine ball hook’em drill was the most different to a pitch, and the towel drill was the most similar. This work demonstrates the first collective approach to studying the biomechanics of frequently used baseball pitching constraint drills

    Biochemical Validation of Patient-Reported Symptom Onset Time in Patients With ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

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    AbstractObjectivesThis study evaluated a biochemical validation of patient-reported symptom onset time in patients with ST-segment elevation myocardial infarction (STEMI).BackgroundSymptom onset time is an important metric but has never been formally validated.MethodsThe Mayo Clinic Percutaneous Coronary Intervention (PCI) Registry was interrogated to obtain baseline, procedural, and outcome data on 607 STEMI patients undergoing primary PCI. Biochemical onset time was determined by backward extrapolation of serial increasing cardiac troponin T (cTnT) measurements.ResultsThe median patient-reported onset time was 12 min later than the calculated time of first cTnT increase and was therefore estimated to be 4.2 h later than the biochemical onset time (interquartile range: 1.9 to 11.1 h; p < 0.001), assuming a 4-h interval between coronary occlusion and first cTnT increase. Conventional ischemic time showed no association with infarct size (correlation with peak cTnT: r = 0.023; p = 0.61) or 1-year mortality (hazard ratio: 0.97 per doubling; 95% confidence interval: 0.68 to 1.40; p = 0.88). However, after recalculation of ischemic time with biochemical onset time, significant associations with infarct size (r = 0.14; p = 0.001) and 1-year mortality (hazard ratio: 1.70 per doubling; 95% confidence interval: 1.20 to 2.40; p = 0.003) were found. When underestimation of ischemic time by patient-reported onset time increased, so did the risk of mortality.ConclusionsAlthough our point estimate should be interpreted with caution, our study indicates that the actual onset of STEMI is likely to be earlier than the patient-reported onset time. Recalculation of ischemic time with biochemical onset time greatly enhanced its prognostic value. Underestimation of ischemic time by patient-reported onset time occurred more often in high-risk patients

    Inflammatory Burden of Cardiac Allograft Coronary Atherosclerotic Plaque Is Associated With Early Recurrent Cellular Rejection and Predicts a Higher Risk of Vasculopathy Progression

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    ObjectivesThis study was designed to investigate tissue characterization of the coronary allograft atherosclerotic plaque with virtual histology intravascular ultrasound (VH-IVUS) imaging to assess the presence and predictors of vessel wall inflammation and its significance in cardiac allograft vasculopathy (CAV) progression.BackgroundA unique form of accelerated atherosclerosis, CAV remains the leading cause of late morbidity and mortality in heart transplant patients. The pathogenesis of CAV is not fully elucidated.MethodsA total of 86 patients with coronary allograft vasculopathy underwent VH-IVUS examination of the left anterior descending coronary artery 3.61 ± 3.04 years following cardiac transplantation. Based on the VH-IVUS plaque characteristics, coronary allograft plaque was divided on virtual histology intravascular ultrasound-derived “inflammatory” (VHD-IP) (necrotic core and dense calcium ≥30%) and “noninflammatory” plaque (VHD-NIP) (necrotic core and dense calcium <30%). Total rejection scores were calculated based on the 2004 International Society of Heart and Lung Transplantation rejection grading system.ResultsIn the whole study population, the mean percentage of fibrous, fibrofatty, dense calcified, and necrotic core plaques in a mean length of 62.3 ± 17.4 mm of the left anterior descending coronary artery were 50 ± 17%, 16 ± 11%, 15 ± 11%, and 18 ± 9%, respectively. Patients with a 6-month total rejection score >0.3 had significantly higher incidence of VHD-IP than those with a 6-month total rejection score ≤0.3 (69% vs. 33%, p = 0.011). The presence of VHD-IP at baseline was associated with a significant increase in plaque volume (2.42 ± 1.78 mm3/mm vs. –0.11 ± 1.65 mm3/mm, p = 0.010), plaque index (7 ± 9% vs. 0 ± 8%, p = 0.04), and remodeling index (1.24 ± 0.44 vs. 1.09 ± 0.36, p = 0.030) during 12 months of follow-up when compared with the presence of VHD-NIP at baseline and during follow-up.ConclusionsThe presence of VHD-IP as assessed by VH-IVUS is associated with early recurrent rejection and with higher subsequent progression of CAV. A VH-IVUS assessment may add important information in the evaluation of transplant recipients

    Procedural Factors Associated With Percutaneous Coronary Intervention-Related Ischemic Stroke

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    ObjectivesThis study sought to determine whether procedural factors during percutaneous coronary intervention (PCI) are associated with the occurrence of ischemic stroke or transient ischemic attack (PCI-stroke).BackgroundStroke is a devastating complication of PCI. Demographic predictors are nonmodifiable. Whether PCI-stroke is associated with procedural factors, which may be modifiable, is unknown.MethodsWe performed a single-center retrospective study of 21,497 PCI hospitalizations between 1994 and 2008. We compared procedural factors from patients who suffered an ischemic stroke or transient ischemic attack related to PCI (n = 79) and a control group (n = 158), and matched them 2:1 based on a predicted probability of stroke developed from a logistic regression model.ResultsPCI-stroke procedures involved the use of more catheters (median: 3 [quarter (Q) 1, Q3: 3, 4] vs. 3 [Q1, Q3: 2, 3], p < 0.001), greater contrast volumes (250 ml vs. 218 ml, p = 0.006), and larger guide caliber (median: 7-F [Q1, Q3: 6, 8] vs. 6-F [Q1, Q3: 6, 8], p < 0.001). The number of lesions attempted (1.7 ± 0.8 vs. 1.5 ± 0.8, p = 0.14) and stents placed (1.4 ± 1.2 vs. 1.2 ± 1.1, p = 0.35) were similar between groups, but PCI-stroke patients were more likely to have undergone rotational atherectomy (10% vs. 3%, p = 0.029). Overall procedural success was lower in the PCI-stroke group compared with controls (71% vs. 85%, p = 0.017). Evaluation of the entire PCI population revealed no difference in the rate of PCI-stroke between radial and femoral approaches (0.4% vs. 0.4%, p = 0.78).ConclusionsIschemic stroke related to PCI is associated with potentially modifiable technical parameters. Careful procedural planning is warranted, particularly in patients at increased risk

    Sex differences in atheroma burden and endothelial function in patients with early coronary atherosclerosis

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    Aims Women and men have different clinical presentations and outcomes in coronary artery disease (CAD). We tested the hypothesis that sex differences may influence coronary atherosclerotic burden and coronary endothelial function before development of obstructive CAD. Methods and results A total of 142 patients (53 men, 89 women; mean ± SD age, 49.3 ± 11.7 years) with early CAD simultaneously underwent intravascular ultrasonography and coronary endothelial function assessment. Atheroma burden in the left main and proximal left anterior descending (LAD) arteries was significantly greater in men than women (median, 23.0% vs. 14.1%, P = 0.002; median, 40.1% vs. 29.3%, P = 0.001, respectively). Atheroma eccentricity in the proximal LAD artery was significantly higher in men than women (median, 0.89 vs. 0.80, P = 0.04). The length of the coronary segments with endothelial dysfunction was significantly longer in men than women (median, 39.2 vs. 11.1 mm, P = 0.002). In contrast, maximal coronary flow reserve was significantly lower in women than men (2.80 vs. 3.30, P < 0.001). Sex was an independent predictor of atheroma burden in the left main and proximal LAD arteries (both P < 0.05) by multivariate analysis. Conclusion Men have greater atheroma burden, more eccentric atheroma, and more diffuse epicardial endothelial dysfunction than women. These results suggest that men have more severe structural and functional abnormalities in epicardial coronary arteries than women, even in patients with early atherosclerosis, which may result in the higher incidence rates of CAD and ST-segment myocardial infarction in men than wome

    Long-term outcomes of fractional flow reserve-guided vs. angiography-guided percutaneous coronary intervention in contemporary practice

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    Aims Fractional flow reserve (FFR) is the reference standard for the assessment of the functional significance of coronary artery stenoses, but is underutilized in daily clinical practice. We aimed to study long-term outcomes of FFR-guided percutaneous coronary intervention (PCI) in the general clinical practice. Methods and results In this retrospective study, consecutive patients (n = 7358), referred for PCI at the Mayo Clinic between October 2002 and December 2009, were divided in two groups: those undergoing PCI without (PCI-only, n = 6268) or with FFR measurements (FFR-guided, n = 1090). The latter group was further classified as the FFR-Perform group (n = 369) if followed by PCI, and the FFR-Defer group (n = 721) if PCI was deferred. Clinical events were compared during a median follow-up of 50.9 months. The Kaplan-Meier fraction of major adverse cardiac events at 7 years was 57.0% in the PCI-only vs. 50.0% in the FFR-guided group (P = 0.016). Patients with FFR-guided interventions had a non-significantly lower rate of death or myocardial infarction compared with those with angiography-guided interventions [hazard ratio (HR): 0.85, 95% CI: 0.71-1.01, P = 0.06]; the FFR-guided deferred-PCI strategy was independently associated with reduced rate of myocardial infarction (HR: 0.46, 95% CI: 0.26-0.82, P = 0.008). After excluding patients with FFR of 0.75-0.80 and deferring PCI, the use of FFR was significantly associated with reduced rate of death or myocardial infarction (HR: 0.80, 95% CI: 0.66-0.96, P = 0.02). Conclusion In the contemporary practice, an FFR-guided treatment strategy is associated with a favourable long-term outcome. The current study supports the use of the FFR for decision-making in patients undergoing cardiac catheterizatio

    A Total of 1,007 Percutaneous Coronary Interventions Without Onsite Cardiac Surgery Acute and Long-Term Outcomes

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    ObjectivesWe sought to compare clinical outcomes of elective percutaneous coronary intervention (PCI) and primary PCI for ST-segment elevation myocardial infarction (STEMI) at a community hospital without onsite cardiac surgery to those at a tertiary center with onsite cardiac surgery.BackgroundDisagreement exists about whether hospitals with cardiac catheterization laboratories, but without onsite cardiac surgery, should develop PCI programs. Primary PCI for STEMI at hospitals without onsite cardiac surgery have achieved satisfactory outcomes; however, elective PCI outcomes are not well defined.MethodsA total of 1,007 elective PCI and primary PCI procedures performed from March 1999 to August 2005 at the Immanuel St. Joseph’s Hospital–Mayo Health System (ISJ) in Mankato, Minnesota, were matched one-to-one with those performed at St. Mary’s Hospital (SMH) in Rochester, Minnesota. Strict protocols were followed for case selection and PCI program requirements. Clinical outcomes (in-hospital procedural success, death, any myocardial infarction, Q-wave myocardial infarction, and emergency coronary artery bypass surgery) and follow-up survival were compared between groups.ResultsAmong 722 elective PCIs, procedural success was 97% at ISJ compared with 95% at SMH (p = 0.046). Among 285 primary PCIs for STEMI, procedural success was 93% at ISJ and 96% at SMH (p = 0.085). No patients at ISJ undergoing PCI required emergent transfer for cardiac surgery. Survival at two years’ follow-up by treatment location was similar for patients with elective PCI and primary PCI.ConclusionsSimilar clinical outcomes for elective PCI and primary PCI were achieved at a community hospital without onsite cardiac surgery compared with those at a tertiary center with onsite cardiac surgery using a prospective, rigorous protocol for case selection and PCI program requirements
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