Usefulness of cardiac index and peak exercise oxygen consumption for determining priority for cardiac transplantation

Predicting High-Risk Patients and High-Risk Outcomes in Heart Failure

Identifying patients with heart failure at high risk for poor outcomes is important for patient care, resource allocation, and process improvement. Although numerous risk models exist to predict mortality, hospitalization, and patient-reported health status, they are infrequently used for several reasons, including modest performance, lack of evidence to support routine clinical use, and barriers to implementation. Artificial intelligence has the potential to enhance the performance of risk prediction models, but has its own limitations and remains unproved.

Comparison of Hemodynamic Factors Predicting Prognosis in Heart Failure: A Systematic Review

Objectives: We systematically reviewed the literature to address the question of which of the three hemodynamic factors predicts prognosis best in heart failure patients when directly compared to each other: cardiac output, preload or afterload. Methods: Prognostic studies in heart failure (HF) were searched that included at least two of the three hemodynamic variables: (1) cardiac output or cardiac index (CI), (2) preload represented by pulmonary capillary wedge pressure (PCWP) and (3) afterload simplified to systolic blood pressure (SBP). Critical appraisal was done according to the QUIPS format for prognostic studies. The main endpoint was all-cause mortality, which could be combined with other endpoints. We report the number of studies in which CI, PCWP and SBP remained significant prognostic predictors in multivariate analysis. We also assessed whether hemodynamic predictors of prognosis varied in four different HF-populations. Results: Included were 18 studies containing a multivariate analysis. PCWP was an independent predictor of prognosis in 10 of 18 studies, SBP in 3 of 14 studies and CI in none of 18 studies. Results were not specific for any of the HF-populations. Conclusions: A higher PCWP and lower SBP are independent predictors of poor prognosis in HF. In spite of the frequently used concept behind HF, this review demonstrates that CI is not an independent predictor of prognosis in HF.

Hemodynamic Predictors of Heart Failure Morbidity and Mortality: Fluid or Flow?

BACKGROUND

Patients with advanced heart failure may continue for prolonged times with persistent hemodynamic abnormalities; intermediate- and long-term outcomes of these patients are unknown.

METHODS AND RESULTS

We used ESCAPE (Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness) trial data to examine characteristics and outcomes of patients with invasive hemodynamic monitoring during an acute heart failure hospitalization. Patients were stratified by final measurement of cardiac index (CI; L/min/m2) and pulmonary capillary wedge pressure (PCWP; mmHg) before catheter removal. The study groups were CI ≥ 2/PCWP < 20 (n = 74), CI ≥ 2/PCWP ≥ 20 (n = 37), CI < 2/PCWP < 20 (n = 23), and CI < 2/PCWP ≥ 20 (n = 17). Final CI was not associated with the combined risk of death, cardiovascular hospitalization, and transplantation (hazard ratio [HR]1.03, 95% confidence interval 0.96-1.11 per 0.2 L/min/m2 decrease, P = .39), but final PCWP ≥ 20 mmHg was associated with increased risk of these events (HR 2.03, 95% confidence interval 1.31-3.15, P < .01), as was higher final right atrial pressure (HR 1.09, 95% confidence interval 1.06-1.12 per mmHg increase, P < .01).

CONCLUSION

Final PCWP and final right atrial pressure were stronger predictors of postdischarge outcomes than CI in patients with advanced heart failure. The ability to lower filling pressures appears to be more prognostically important than improving CI in the management of patients with advanced heart failure. ClinicalTrials.govIdentifier: NCT00000619.

Ten Years Experiences With Preoperative Evaluation Clinic for Day Admission Cardiac and Major Vascular Surgical Patients: Model for "Perioperative Anesthesia and Surgical Home"

Admission on the day of surgery for elective cardiac and noncardiac surgery is the prevalent practice in North America and Canada. This approach realizes medical, psychological and logistical benefits, and its success is predicated on an effective outpatient preoperative evaluation. The establishment of a highly functional preoperative clinic with a comprehensive set up and efficient logistical pathways is invaluable. This notion in recent years has included the entire perioperative period, and the concept of a perioperative anesthesia/surgical home (PASH) is gaining popularity. The anesthesiologists as perioperative physicians can organize and lead the entire process from the preoperative evaluation, through the hosptial discharge. The functions of the PASH include preoperative optimization of medical conditions and psychological preparation of the patients and their support system; the care in the operating room and intensive care unit; pain management; respiratory therapy; cardiac rehabilitation; and specialized nutrition. Along with oversight of the medical issues, the preoperative visit is an opportune time for counseling, clarification of expectations and discussion of research, as well as for utilization of various informatics systems to consolidate the pertinent information and distribute it to relevant health care providers. We review the scientific foundation and practical applications of a preoperative visit and share our experience with the development of the preoperative evaluation clinic, designed specifically for cardiac and major vascular patients scheduled for day admission surgery. The ultimate goal of preoperative evaluation clinic is to ensure a safe, efficient, and cost-effective perioperative care for patients undergoing a complex type of surgery.

Patient selection for advanced heart failure therapy referral

Despite advances in medical therapy for chronic heart failure (HF), advanced HF carries a dismal prognosis. Options such as transplantation and durable mechanical circulatory support have greatly improved outcomes for these patients, but their introduction has introduced significant complexity to patient management. Although much of this management occurs at specialized heart transplant centers, it is the responsibility of the primary cardiologist of the patient with advanced HF to refer patients at the appropriate time and to help them navigate the difficult decisions related to the pursuit of advanced therapies. We present a unique pathway that incorporates guidelines, recent data, and expert opinion to help general cardiologists determine which patients should be referred for transplantation or durable mechanical circulatory support, and when they should be referred. Decision making on referral to the heart transplant center is also summarized.

Characteristics and outcomes of patients with heart failure and discordant findings by right-sided heart catheterization and cardiopulmonary exercise testing

There are limited data integrating findings on right-sided cardiac catheterization and cardiopulmonary exercise testing in ambulatory patients with heart failure. In this study, 187 outpatients with HF referred to the Duke Medical Center for consideration of advanced HF therapies were retrospectively evaluated. All patients had undergone right-sided cardiac catheterization and cardiopulmonary exercise testing; the median cardiac index (CI) was 2.0 L/min/m2 (interquartile range 1.7 to 2.3), and the median peak oxygen consumption was 11.3 ml/kg/min (interquartile range 9.2 to 13.8). Despite aggressive medical therapy, medical management had failed in 97 patients (52%) at 18 months, defined as left ventricular assist device implantation, cardiac transplantation, or death. After multivariate adjustment, factors associated with failure of optimal medical management included percentage achieved of predicted peak oxygen consumption, low CI (i.e., <2 L/min/m2), left ventricular size, and exercise time. Patients with discordant findings on right-sided cardiac catheterization and cardiopulmonary exercise testing were common, occurring in 88 patients (47%). The most common profile was preserved CI but reduced functional capacity, and these patients remained at high risk for requiring advanced therapies, whereas patients with reduced CIs but preserved exercise capacity were uncommon. In conclusion, low CI was independently associated with higher rates of death, transplantation, and left ventricular assist device implantation in this study. Also, patients with preserved CIs at rest but poor functional capacity, so-called cardiac insufficiency, were commonly encountered and had poor outcomes with medical management.

Cardiopulmonary responses to exercise and its utility in patients with aortic stenosis

Utility of cardiopulmonary exercise test is unknown in patients with aortic stenosis. In this retrospective study, we examined the maximal indexes of cardiopulmonary testing at peak exercise in 155 consecutive patients with aortic valve area of ≤ 1.5 cm(2) who were referred for this test. The patients were passively followed up to assess their effect on the primary end point of all-cause mortality. We found that the absolute peak oxygen consumption (VO2) was significantly reduced in these patients, with age and gender-predicted peak VO2 of 80 ± 23%. Peak VO2 was markedly reduced (<80% of predicted) in 54% of patients. During a follow-up of 5 ± 4 years, a total of 41 patients died, and 72 underwent aortic valve replacement. Survival was significantly better in patients with higher absolute peak VO2 (hazard ratio [HR] 0.87, 95% confidence interval [CI] 0.80 to 0.93, p <0.001) and higher oxygen pulse (HR 0.80, 95% CI 0.74 to 0.9, p <0.001). In 83 patients who did not undergo valve replacement, higher peak VO2 and oxygen pulse were associated with better survival (HR 0.83, 95% CI 0.71 to 0.97, p = 0.024 and HR 0.80, 95% CI 0.66 to 0.96, p = 0.02, respectively). In conclusion, the peak VO2 is significantly reduced in patients with aortic stenosis. Higher peak VO2 is independently associated with better survival in these patients irrespective of whether they undergo valve replacement.

Safety of symptom-limited cardiopulmonary exercise testing in patients with aortic stenosis

BACKGROUND

There are no published data on the safety of cardiopulmonary exercise testing in patients with aortic stenosis.

METHODS

In this retrospective descriptive study, we examined 347 consecutive patients with aortic stenosis who underwent cardiopulmonary exercise testing at a tertiary referral center. We recorded major events including death, nonfatal major events (cardiac arrest, symptomatic or sustained ventricular or supraventricular tachycardia, myocardial infarction, and syncope), and minor events such as hypotension, nonsustained supraventricular and ventricular arrhythmias, positive electrocardiographic changes, and angina.

RESULTS

Of 347 patients, 65 (19%) had mild, 145 (42%) had moderate, and 137 (40%) had severe aortic stenosis by echocardiographic criteria. No major events occurred during the tests. Minor events occurred in a total of 97 patients (28%), including 10 patients who developed supraventricular arrhythmias without hypotension; and one who had asymptomatic nonsustained ventricular tachycardia.

CONCLUSION

Symptom-limited cardiopulmonary exercise testing in cardiology-referred patients with aortic stenosis with preserved systolic function appears to be associated with very low risk of major adverse cardiovascular events during testing.

Heart transplantation

PURPOSE OF REVIEW

This paper briefly and subjectively reviews a number of the modest or tentative, but noteworthy, advances in heart transplantation that have been made during the past 18 months or so.

RECENT FINDINGS

The advances reviewed concern the selection of recipients, the management of the heart transplantation waiting list, the management of donors, post-heart transplant monitoring of immunological status, the early diagnosis of rejection, the role of mammalian target of rapamycine inhibitors and induction agents, and the definition and grading of cardiac allograft vasculopathy.

SUMMARY

The findings reviewed indicate progress in the clarification of issues that were in most cases already being investigated. Further studies will in general be needed before corresponding measures are adopted in clinical practice.