Veronica Franco

A Multicenter Study of Noninvasive Cardiac Output by Bioreactance During Symptom-limited Exercise

BACKGROUNDnHemodynamic responses to exercise were assessed in patients with varying degrees of chronic heart failure (CHF) to determine the feasibility of using bioreactance during exercise testing in multicenter studies of CHF.nnnMETHODS AND RESULTSnA total of 210 symptomatic CHF patients and 22 subjects without heart failure were subjected to symptom-limited exercise testing on a bicycle (105) or treadmill (127) while measuring gas exchange for VO(2), cardiac output (CO) noninvasively by a bioreactance technique, heart rate, and blood pressure. Peak CO (pCO) and VO(2) (pVO(2)) during exercise were lower in patients with higher New York Heart Association (NYHA) class, in females and in older patients. Multiple linear regression analysis showed that pCO (L/min)=19.6+4.M -2.1.NYHA+1.9.G -0.09.Age, where M=1 for treadmill and 0 for bicycle and G=1 for males and 0 for females. Similarly, pVO(2) (mL/kg/min)=24+2.1.M -2.9.NYHA+1.26.G -0.08.Age. VO(2) and CO were also highly correlated to each other: pCO (mL/kg/min)=0.059+0.007.pVO(2)+0.036.M -0.025.G. Similar correlations were determined for other parameters of exercise, including left ventricular power, and the ratio of peak/resting VO(2) (cardiovascular reserve), the ratio of peak/resting CO (cardiac reserve), and total peripheral vascular resistance.nnnCONCLUSIONnBioreactance-based noninvasive measurements of CO at rest and during exertion identified abnormalities of cardiovascular function consistent with those identified by pVO(2) and in prior studies using invasive CO measurements. This technique might therefore be useful for indexing disease severity, prognostication, and for tracking responses to treatment in clinical practice and in clinical trials.

Right Ventricular Remodeling in Pulmonary Hypertension

The right ventricle (RV) is in charge of pumping blood to the lungs for oxygenation. Pulmonary arterial hypertension (PAH) is characterized by high pulmonary vascular resistance and vascular remodeling, which results in a striking increase in RV afterload and subsequent failure. There is still unexploited potential for therapies that directly target the RV with the aim of supporting and protecting the right side of the heart, striving to prolong survival in patients with PAH.

Cardiopulmonary Exercise Test in Chronic Heart Failure: Beyond Peak Oxygen Consumption

Patients with cardiovascular diseases commonly present with exercise intolerance, clinically manifest as shortness of breath and fatigue, and these symptoms have important prognostic implications. Cardiopulmonary exercise testing is a well-established method for evaluation of cardiopulmonary diseases. It provides an objective assessment of maximal aerobic capacity (peak VO2), estimates prognosis, and allows the physician to discriminate among many subtle and often overlapping etiologies. This review focuses on the evaluation of important exercise parameters, in addition to the peak VO2, during cardiopulmonary exercise testing.

Cardiopulmonary exercise testing in the MRI environment.

Maximal oxygen consumption ([Formula: see text]max) measured by cardiopulmonary exercise testing (CPX) is the gold standard for assessment of cardiorespiratory fitness. Likewise, cardiovascular magnetic resonance (CMR) is the gold standard for quantification of cardiac function. The combination of CPX and CMR may offer unique insights into cardiopulmonary pathophysiology; however, the MRI-compatible equipment needed to combine these tests has not been available to date. We sought to determine whether CPX testing in the MRI environment, using equipment modified for MRI yields results equivalent to those obtained in standard exercise physiology (EP) lab. Ten recreationally trained subjects completed [Formula: see text]max tests in different locations; an EP laboratory and an MRI laboratory, using site specific equipment. CMR cine images of the heart were acquired before and immediately after maximal exercise to measure cardiac function. Subjects in all tests met criteria indicating that peak exercise was achieved. Despite equipment modifications for the MRI environment, [Formula: see text]max was nearly identical between tests run in the different labs (95% lower confidence limit (LCL)u2009u2009=u2009u20090.8182). The mean difference in [Formula: see text]max was less than 3.40u2009ml (kg/min)(-1), within the variability expected for tests performed on different days, in different locations, using different metabolic carts. MRI performed at rest and following peak exercise stress indicated cardiac output increased from 5.1u2009u2009±u2009u20091.0 l min(-1) to 16.4u2009u2009±u2009u20095.6 l min(-1), LVEF increased from 65.2u2009u2009±u2009u20093.3% to 78.4u2009u2009±u2009u20094.8%, while RVEF increased from 52.8u2009u2009±u2009u20095.3% to 63.4u2009u2009±u2009u20095.3%. Regression analysis revealed a significant positive correlation between [Formula: see text]max and stroke volume (Ru2009u2009=u2009u20090.788, Pu2009u2009=u2009u20090.006), while the correlation with cardiac output did not reach statistical significance (Ru2009u2009=u2009u20090.505, Pu2009u2009=u2009u20090.137). [Formula: see text]max CPX testing can be effectively performed in the MRI environment, enabling direct combination of physiological data with advanced post-exercise imaging in the same test session.

Epidemiology of Sudden Cardiac Death in Patients with Heart Failure

Mortality in congestive heart failure (CHF) usually occurs from either progressive worsening of cardiac pump failure or sudden cardiac death (SCD). Medical interventions that counter neurohormonal changes slow the progression of CHF and also prevent SCD. The benefits of medical therapy on SCD prevention have been variable, depending on the type of medical therapy. This article discusses the incidence, prediction, and prevention of SCD in CHF due to ischemic and nonischemic cardiomyopathy.

Safety and efficacy of transition from inhaled treprostinil to parenteral treprostinil in selected patients with pulmonary arterial hypertension

Guidelines for the treatment of pulmonary arterial hypertension (PAH) recommend sequential add-on therapy for patients who deteriorate or fail to improve clinically. However, it is not known whether these patients also benefit from transitioning from inhaled prostacyclins to parenteral prostacyclins. We sought to characterize PAH patients receiving inhaled treprostinil who were transitioned to parenteral treprostinil. We conducted a multicenter retrospective study at 7 PAH centers and collected reasons, methods, safety, and outcome of patients transitioned from inhaled treprostinil to parenteral treprostinil. Twenty-six patients with pulmonary hypertension in group 1, 4, or 5 transitioned from inhaled treprostinil to parenteral treprostinil (10 intravenous, 16 subcutaneous). Twenty-four patients were also on one or two oral therapies. Reasons for transition were clinical deterioration, lack of clinical improvement, and pregnancy (19, 6, and 1 patients, respectively). Transitions occurred in hospital, clinic, or home (17, 7, and 2 patients, respectively). Parenteral infusion was started after the last inhaled treatment at maintenance dose (13 patients), after the inhaled therapy was downtitrated to 18 μg (6 patients), or with an overlap of inhaled downtitration with parenteral uptitration (7 patients). The transition was safe; side effects included symptoms of prostacyclin overdose. Patients were followed for 3–18 months. At 3 months, 8 patients improved, 17 maintained their functional class, and 1 continued to deteriorate. In conclusion, selected PAH patients can be safely transitioned from inhaled treprostinil to parenteral treprostinil using a variety of methodologies in different settings with the expectation that patients will improve or at least remain clinically stable.

Conversion From Sildenafil to Tadalafil: Results From the Sildenafil to Tadalafil in Pulmonary Arterial Hypertension (SITAR) Study

Purpose: Among phosphodiesterase type 5 inhibitors, tadalafil offers clinicians a once-daily alternative to 3 times daily sildenafil for the treatment of pulmonary arterial hypertension (PAH). This study assessed the safety and patient satisfaction with conversion from sildenafil to tadalafil. Methods: In this multicenter, prospective, 6-month study, patients with PAH were instructed to take their last dose of sildenafil in the evening and initiate tadalafil 40 mg/d the next morning. Patients completed the Treatment Satisfaction Questionnaire for Medication at baseline and 30, 90, and 180 days after transition to assess PAH symptoms and patient satisfaction. Safety was assessed on the basis of recorded adverse events (AEs). Results: Of the 35 patients who met the study criteria, 56% were receiving ≥2 PAH therapies. At the time of transition, the sildenafil dose ranged from 40 to 300 mg/d, with 20% of the patients on >20 mg of sildenafil 3 times daily. Transition to tadalafil was generally well tolerated, and the incidence of common AEs, except for myalgia, appeared to decrease over time on tadalafil therapy. Five (14%) patients switched back to sildenafil. A greater percentage of patients were satisfied than were dissatisfied after conversion to tadalafil (55% vs 19% at 90 days), while 26% felt about the same degree of satisfaction. Conversion to tadalafil resulted in significant improvement in patient ratings of therapy convenience. Conclusions: Transition of patients from sildenafil to tadalafil was usually well tolerated, with improved convenience and may enhance treatment satisfaction.

Pilot Randomized Controlled Trial to Reduce Readmission for Heart Failure Using Novel Tablet and Nurse Practitioner Education

BACKGROUNDnHeart failure education programs are not standardized. The best form of education is unclear. We evaluated whether addition of a novel tablet application to nurse practitioner (NP) education was superior to NP education alone in reducing 30-day readmission after heart failure hospitalization.nnnMETHODSnFrom February 2015-March 2016, patients admitted to a quaternary academic center with primary diagnosis of heart failure were randomized to 1) treatment - NP education plus tablet application (interactive conditional logic program that flags patient questions to medical staff), or 2) control - NP education. The primary outcome was reduction in 30-day readmission rate. Secondary outcomes included satisfaction and education assessed via survey.nnnRESULTSnRandomization included 60 patients to treatment and 66 to control. A total of 13 patients withdrew prior to intervention (treatment nxa0=xa04, control nxa0=xa01) or were lost to follow-up (treatment nxa0=xa03, control nxa0=xa05). The 30-day readmission rate trended lower for treatment compared with control, but results were not statistically significant (13.2% [7/53], 26.7% [16/60], respectively, Pxa0=xa0.08). Similarly, satisfaction trended higher with treatment than control (Pxa0=xa0.08). Treatment patients rated explanations from their physicians higher than control (Always: 83.7%, 55.8%, respectively, Pxa0=xa0.01).nnnCONCLUSIONSnNP education plus tablet use was not associated with significantly lower 30-day readmission rates in comparison with NP alone, but a positive trend was seen. Patient satisfaction trended higher and heart failure explanations were better with NP education plus tablet. A larger study is needed to determine if NP education plus tablet reduces readmission rates following heart failure admission.

Management of Pulmonary Hypertension

Pulmonary hypertension (PH) due to left heart disease, or WHO group 2 PH, is the most frequent cause of PH. It affects approximately 50% to 60% of patients with heart failure with preserved ejection fraction as well as 60% of those with heart failure with reduced ejection fraction and contributes significantly to disease progression and unfavorable outcomes. The diagnosis of PH is associated with poor prognosis and significant morbidity and mortality.

Pulmonary Hypertension in Women

Prevalence of pulmonary arterial hypertension (PAH) is higher in women, and the mechanism remains unclear. Prognosis is overall better for female compared with male patients with PAH. Pregnancy is associated with significant risk, mortality, and morbidity in patients with PAH; consensus guidelines recommend against pregnancy and counsel about early termination in these patients. Recent advances in treatment showed improvement in prognosis in small case reports of pregnant patients with PAH, particularly with the early use of parental prostacyclin. Education remains fundamental for women with PAH of childbearing age for pregnancy prevention as well as discussion about birth control methods.