Comparative accuracy of supine-only and combined supine-prone myocardial perfusion imaging in men.

BACKGROUND: Combined supine-prone myocardial perfusion imaging (CSP MPI) has been shown to reduce attenuation artifact in comparison to supine-only (SU) MPI in mixed-gender populations with varying risk for coronary artery disease (CAD), often where patients served as their own controls. However, there is limited direct comparison of these imaging strategies in men. METHODS: 934 male patients underwent CSP or SU MPI. Diagnostic certainty of interpretation was compared. Within the cohort, 116 were referred for left heart catheterization (LHC) to assess for CAD. Sensitivity, specificity, and area under the curve (AUC) were compared with additional analysis based on body mass index (BMI). RESULTS: 597 patients completed the SU protocol and 337 patients completed the CSP protocol. Equivocal studies were seen more frequently in the SU group (13%) than in the CSP group (4%, P < .001). At catheterization, the specificity for CSP MPI of 70% was higher than 40% for SU MPI (P = .032). The CSP AUC (0.80 ± 0.06) was significantly larger than SU AUC (0.57 ± 0.05, P = .004). CSP specificity was significantly higher in obese patients. CONCLUSIONS: CSP MPI increases diagnostic certainty and improves test accuracy for CAD detection in men with CAD risk factors, especially obese patients, compared to SU MPI.

Pulmonary hypertension in hypertensive patients: association with diastolic dysfunction and increased pulmonary vascular resistance.

BACKGROUND: Pulmonary hypertension (PH) in patients with systemic hypertension and preserved ejection fraction (PEF) has been described. However, the pathophysiology and consequences are not entirely clear. We sought to distinguish the clinical and anatomic features among hypertensive patients with or without coexistent PH. METHODS: Echocardiograms and records of hypertensive patients with left ventricular (LV) hypertrophy and PEF from January 2009 to January 2011 were reviewed. We identified 174 patients, including 36 with PH (calculated pulmonary artery systolic pressure [PASP] ≥ 35 mmHg), and 138 with normal pulmonary pressures. RESULTS: Hypertensive patients with PH were older (76 ± 13 vs. 65 ± 13 years, P < 0.0001), more often female (91, 70%), had lower estimated glomerular filtration rate (eGFR) (63 ± 44 vs. 88 ± 48 mL/min, P = 0.002), and higher pro-BNP levels (3141 ± 4253 vs. 1219 ± 1900 pg/mL, P = 0.003). PH patients also had larger left atrial areas (23.7 ± 3.8 vs. 20.8 ± 4.6 cm(2) , P = 0.002), evidence of diastolic dysfunction (i.e., septal E/e' 17.6 ± 8.6 vs. 12.7 ± 4.4, P = 0.0005), and higher calculated peripheral vascular resistance (PVR) (2.3 ± 1.1 vs. 1.6 ± 0.4, P < 0.0001). Both PVR and septal E/e' showed strong linear correlation with PASP (P < 0.0001 and P < 0.0001, respectively). CONCLUSIONS: Hypertension in elderly patients is frequently complicated by LV diastolic dysfunction and secondary PH. These hypertensive patients tended to have reduced renal function and higher pro-BNP. Because of the known morbidity and mortality associated with PH, these observations have potentially important implications for target medical therapy.

Myopathy Associated With Statins and SGLT2 - A Review of Literature.

Drug-induced myopathy is a well-described clinical entity characterized by muscle damage leading to symptoms ranging from myalgias to rhabdomyolysis and acute kidney injury. Many pharmacotherapies are known to precipitate myopathic symptoms. Recent case reports suggest a potential relationship between the use of sodium/glucose cotransport 2 (SGLT2) inhibitors and onset of myopathy. The pathogenesis of this has yet to be elucidated. The relevance of this association is augmented by the recent popularity of SGLT2 inhibitors as well as the tendency for them to be prescribed alongside statins. This study reviewed the literature on the incidence and mechanism of drug-induced myopathy in patients with type 2 diabetes mellitus who are taking SGLT2 inhibitors with and without the use of statins.

Influence of Pregnancy in Patients With Congenital Long QT Syndrome.

Congenital long QT syndrome (LQTS) is a disorder of myocardial repolarization and is characterized by a prolonged QT interval on an electrocardiogram. A prolonged QT predisposes patients to an increased risk of syncope and sudden cardiac death secondary to polymorphic ventricular tachycardia. Several mutations linked to the LQTS have been identified, the most common of which have been found in the potassium channel KCNQ1 (LQT1) and hERG (LQT2) genes and in the sodium channel SCN5A (LQT3) gene. Female sex is an independent risk factor for the development of torsades de pointes in LQTS. Furthermore, although pregnancy may be associated with protection against cardiac events in LQTS, the 9-month postpartum period represents a time of increased arrhythmogenicity. Interestingly, these cardiac events during the postpartum period are more common in patients with LQT2. The precise mechanisms that influence the cardiac repolarization during the postpartum period are unclear. Beta-blockers are considered reasonably safe during pregnancy and should be continued or initiated in patients with LQTS to reduce the risk of cardiac events. Implantable cardioverter defibrillators are safe in pregnancy, and there is no evidence that pregnant women with these devices are at any greater risk for adverse complications solely on the grounds of having the device.

Metrics of quality care in veterans: correlation between primary-care performance measures and inappropriate myocardial perfusion imaging.

BACKGROUND: Approximately 10% to 20% of myocardial perfusion imaging (MPI) tests are inappropriate based on professional-society recommendations. The correlation between inappropriate MPI and quality care metrics is not known. HYPOTHESIS: Inappropriate MPI will be associated with low achievement of quality care metrics. METHODS: We conducted a retrospective cross-sectional investigation at a single Veterans Affairs medical center. Myocardial perfusion imaging tests ordered by primary-care clinicians between December 2010 and July 2011 were assessed for appropriateness (by 2009 criteria). Using documentation of the clinical encounter where MPI was ordered, we determined how often quality care metrics were achieved. RESULTS: Among 516 MPI patients, 52 (10.1%) were inappropriate and 464 (89.9%) were not inappropriate (either appropriate or uncertain). Hypertension (82.2%), diabetes mellitus (41.3%), and coronary artery disease (41.1%) were common. Glycated hemoglobin levels were lower in the inappropriate MPI cohort (6.6% vs 7.5%; P = 0.04). No difference was observed in the proportion with goal hemoglobin (62.5% vs 46.3% for appropriate/uncertain; P = 0.258). Systolic blood pressure was not different (132 mm Hg vs 135 mm Hg; P = 0.34). Achievement of several other categorical quality metrics was low in both cohorts and no differences were observed. More than 90% of clinicians documented a plan to achieve most metrics. CONCLUSIONS: Inappropriate MPI is not associated with performance on metrics of quality care. If an association exists, it may be between inappropriate MPI and overly aggressive care. Most clinicians document a plan of care to address failure of quality metrics, suggesting awareness of the problem.

Estimation of right atrial and ventricular hemodynamics by CT coronary angiography.

BACKGROUND: Computed tomography coronary angiography (CTCA) provides an accurate noninvasive alternative to the invasive assessment of coronary artery disease. However, a specific limitation of CTCA is inability to assess hemodynamic data. OBJECTIVE: We hypothesized that CTCA-derived measurements of contrast within the superior vena cava (SVC) and inferior vena cava (IVC) would correlate to echocardiographic estimations of right atrial and right ventricular pressures. METHODS: Medical records of all patients who underwent both echocardiography and CTCA in our center were reviewed (n = 32). Standard CTCA was performed with a 64-detector CT using test-bolus method for image acquisition timing and iso-osmolar contrast injection through upper extremity vein. The length of the column of contrast reflux into the inferior vena cava (IVC) was correlated to echocardiographically determine tricuspid regurgitation jet velocity (TRV). SVC area change with contrast injection at the level of the bifurcation of the pulmonary artery was also correlated with IVC sniff response by echocardiogram. RESULTS: The reflux column length was interpretable in 27 of 32 patients with a mean length of 10.1 ± 1.1 mm, and a significant bivariate correlation was observed between reflux column length and the tricuspid regurgitant jet velocity (r = 0.84; P < .0001). Mean SVC distensibility ratio was 0.63 ± 0.03; mean IVC sniff response ratio was 0.53 ± 0.03. SVC distensibility correlated to IVC sniff response with a Pearson r of 0.57 (P = .04). CONCLUSION: Quantification of IVC and SVC contrast characteristics during CTCA provides a feasible and potentially accurate method of estimating right atrial and ventricular pressure.