Reducing radiation dose from myocardial perfusion imaging in subjects with complex congenital heart disease.

INTRODUCTION: The prevalence of defects and effective radiation dose from various myocardial perfusion imaging (MPI) strategies in congenital heart disease (CHD) is unknown. METHODS: We studied 75 subjects with complex CHD (ages 5 to 80 years) referred for MPI between 2002 and 2015. A rest and exercise or pharmacologic stress MPI was performed using 99mTechnetium sestamibi, 82rubidium or 13N-ammonia, and Sodium iodide SPECT (single-photon emission computed tomography), SPECT/CT or Cadmium zinc telluride (CZT) SPECT or PET (positron emission tomography)/CT scanners. Deidentified images were interpreted semi-quantitatively in three batches: stress only MPI, stress/rest MPI, and stress/rest MPI with taking into account a history of ventricular septal defect repair. Effective radiation dose was estimated for stress/rest MPI and predicted for 1-day stress-first (normal stress scans), and for 2-day stress/rest MPI (abnormal stress scans). RESULTS: The median age was 18.6 years. The most common type of CHD was transposition of the great arteries (63%). Rest/stress MPI was abnormal in 43% of subjects and 25% of the abnormal scans demonstrated reversible defects. Of the subjects with abnormal MPI, 33% had significant underlying anatomic coronary artery obstruction. Estimated mean effective radiation dose ranged from 2.1 ± 0.6 mSv for 13N-ammonia PET/CT to 12.5 ± 0.9 mSv for SPECT/CT. Predicted effective radiation dose was significantly lower for stress-first MPI and for 2-day stress/rest protocols. CONCLUSIONS: Due to the relatively high prevalence of abnormal stress MPI, tailored protocols with a stress-first MPI as well as the use of 2-day protocols and advanced imaging technologies including CZT SPECT, novel image reconstruction software, and PET MPI could substantially reduce radiation dose in complex CHD.

A Pilot Study of Inspiratory Muscle Training to Improve Exercise Capacity in Patients with Fontan Physiology.

While the Fontan procedure has improved life expectancy, patients with single ventricle physiology have impaired exercise capacity due to limited increase in pulmonary blood flow during activity. Enhancing the "thoracic pump" using inspiratory muscle training (IMT) may ameliorate this impairment. Adult nonsmokers with Fontan physiology were recruited through Boston Children's Hospital's outpatient clinic. Participants underwent cardiopulmonary exercise testing and pulmonary function testing, followed by 12 weeks of IMT and then repeat testing. The primary endpoint was change in % predicted peak oxygen consumption (VO2). Secondary endpoints were changes in other exercise metrics. Eleven patients (6 male) were enrolled. Median ages at time of enrollment and Fontan completion were 28.8 years (25.7, 45.5) and 7.8 years (3.9, 16.5), respectively. Average baseline maximal inspiratory pressure (MIP) was normal; only 2 patients had MIP <70% predicted. Peak work rate improved significantly from baseline after 12 weeks of IMT (116.5 ± 45.0 to 126.8 ± 47.0 W, P = 0.019). Peak VO2 tended to improve (baseline 68.1 ± 14.3, change + 5.3 ± 9.6% predicted, P = 0.12), as did VE/VCO2 slope (34.1 ± 6.7 to 31.4 ± 3.6, P = 0.12). There was no change in peak tidal volume or MIP. In a small cohort of Fontan patients with mostly normal MIP, IMT was associated with significant improvement in peak work rate and a trend toward higher peak VO2 and improved ventilatory efficiency. Larger studies are needed to determine if this reflects true lack of effect or whether this pilot study was underpowered for effect size, and whether IMT is more narrowly useful for patients with impaired MIP.

A Randomized Trial Comparing Cardiac Rehabilitation to Standard of Care for Adults With Congenital Heart Disease.

BACKGROUND: Cardiac rehabilitation (CR) improves exercise capacity and quality of life while reducing mortality in adults with acquired heart disease. Cardiac rehabilitation has not been extensively studied in adults with congenital heart disease (CHD). METHODS: We performed a prospective, randomized controlled trial (NCT01822769) of a 12-week clinical CR program compared with standard of care (SOC). Participants were ≥16 years old, had moderate or severe CHD, had O2 saturation ≥92%, and had peak O2 consumption ([Formula: see text]) < 80% predicted. We assessed exercise capacity, physical activity, quality of life, self-reported health status, and other variables at baseline and after 12 weeks. The prespecified primary end point was change in [Formula: see text]. RESULTS: We analyzed data on 28 participants (aged 41.1 ± 12.1 years, 50% male), 13 randomized to CR and 15 to SOC. [Formula: see text] averaged 16.8 ± 3.8 mL/kg/min, peak work rate = 95 ± 28 W, and median Minnesota Living with Heart Failure Questionnaire (MLHFQ) score = 27 (interquartile range: 11-44). Cardiac rehabilitation participants were older (48 ± 9 years vs 36 ± 12 years; P = .01), but there were no significant between-group differences in other variables. There were no adverse events related to CR. [Formula: see text] increased in the CR group compared with SOC (+2.2 mL/kg/min, 95% confidence interval: 0.7-3.7; P = .002, age-adjusted +2.7 mL/kg/min; P = .004); there was a nonsignificant improvement in work rate (+8.1 W; P = .13). Among the 25 participants with baseline MLHFQ > 5, there was a clinically important >5-point improvement in 72.7% and 28.6% of CR and SOC participants, respectively ( P = .047). Cardiac rehabilitation was also associated with improved self-assessment of overall health ( P < .04). CONCLUSIONS: Cardiac rehabilitation is safe and is associated with improvement in aerobic capacity and self-reported health status compared with SOC in adults with CHD.

Purulent pericarditis after transbronchial biopsy.

A 28-year-old woman experienced hypotension and unresponsiveness. She had undergone bronchoscopy with needle biopsy 2 weeks before admission to evaluate hilar lymphadenopathy given suspicion of sarcoidosis. She had an elevated white blood cell count of 28,000/µL and a serum creatinine level of 4.0 mg/dL. Echocardiography showed a large pericardial effusion. Pericardiocentesis resulted in removal of 400 mL of yellow-green purulent material that grew Streptococcus milleri, Prevotella, Veillonella, and Peptostreptococcus species. Pericardiectomy and mediastinal washout were performed. Subsequently, her condition rapidly improved. She returned home after 26 days of admission. At 12-month follow-up, the patient had made a full recovery.