Cost-effectiveness of differing perioperative beta-blockade strategies in vascular surgery patients

Effect of beta-blockers on perioperative outcomes in vascular and endovascular surgery: a systematic review and meta-analysis

BACKGROUND

To investigate the role of perioperative beta-blocker use in vascular and endovascular surgery.

METHODS

We performed a systematic review in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement standards. The review protocol was registered with International Prospective Register of Systematic Reviews (registration number:CRD42016038111). We searched electronic databases to identify all randomized controlled trials and observational studies investigating outcomes of patients undergoing vascular and endovascular surgery with or without perioperative beta blockade. We used the Cochrane tool and the Newcastle-Ottawa scale to assess the risk of bias of trials and observational studies, respectively. Random-effects models were applied to calculate pooled outcome data.

RESULTS

We identified three randomized trials, five retrospective cohort studies, and three prospective cohort studies, enrolling a total of 32,602 patients. Our analyses indicated that perioperative use of beta-blockers did not reduce the risk of all-cause mortality [odds ratio (OR) 1.10, 95% confidence interval (CI) 0.59-2.04, P = 0.77], cardiac mortality (OR 2.62, 95% CI 0.86-8.05, P = 0.09), myocardial infarction (OR 0.89, 95% CI 0.59-1.35, P = 0.58), unstable angina (OR 1.34, 95% CI 0.41- 4.38, P = 0.63), stroke (OR 2.45, 95% CI 0.89-6.75, P = 0.08), arrhythmias (OR 0.76, 95% CI 0.41-1.43, P = 0.40), congestive heart failure (OR 1.12, 95% CI 0.77-1.63, P = 0.56), renal failure (OR 1.48, 95% CI 0.90-2.45, P = 0.13), composite cardiovascular events (OR 0.88, 95% CI 0.55-1.40, P = 0.58), rehospitalisation (OR 0.86, 95% CI 0.48-1.52, P = 0.60), and reoperation (OR 1.17, 95% CI 0.42-3.27, P = 0.77) in vascular surgery.

CONCLUSIONS

Beta-blockers do not improve perioperative outcomes in vascular and endovascular surgery.

Economic trends from 2003 to 2010 for perioperative myocardial infarction: a retrospective, cohort study

BACKGROUND

Perioperative myocardial infarction (PMI) is a major surgical complication that is costly and causes much morbidity and mortality. Diagnosis and treatment of PMIs have evolved over time. Many treatments are expensive but may reduce ancillary expenses including the duration of hospital stay. The time-dependent economic impact of novel treatments for PMI remains unexplored. The authors thus evaluated absolute and incremental costs of PMI over time and discharge patterns.

METHODS

Approximately 31 million inpatient discharges were analyzed between 2003 and 2010 from the California State Inpatient Database. PMI was defined using International Classification of Diseases, Ninth Revision, Clinical Modification codes. Propensity matching generated 21,637 pairs of comparable patients. Quantile regression modeled incremental charges as the response variable and year of discharge as the main predictor. Time trends of incremental charges adjusted to 2012 dollars, mortality, and discharge destination was evaluated.

RESULTS

Median incremental charges decreased annually by $1,940 (95% CI, $620 to $3,250); P < 0.001. Compared with non-PMI patients, the median length of stay of patients who experienced PMI decreased significantly over time: yearly decrease was 0.16 (0.10 to 0.23) days; P < 0.001. No mortality differences were seen; but over time, PMI patients were increasingly likely to be transferred to another facility.

CONCLUSIONS

Reduced incremental cost and unchanged mortality may reflect improving efficiency in the standard management of PMI. An increasing fraction of discharges to skilled nursing facilities seems likely a result from hospitals striving to reduce readmissions. It remains unclear whether this trend represents a transfer of cost and risk or improves patient care.

Nitrous oxide and perioperative cardiac morbidity (ENIGMA-II) Trial: rationale and design

BACKGROUND

Globally there are >200 million major surgical procedures undertaken annually, and about 20% of these involve patients who have coronary artery disease. Many receive nitrous oxide, which impairs methionine synthase, thus inhibiting folate synthesis and increasing postoperative homocysteine levels. Nitrous oxide anesthesia leads to postoperative endothelial dysfunction, and there is some evidence that it increases myocardial ischemia and, possibly, myocardial infarction. We have initiated the Nitrous oxide and perioperative cardiac morbidity (ENIGMA-II) Trial to test the hypothesis that in inpatients undergoing anesthesia for major noncardiac surgery, avoidance of nitrous oxide will reduce the incidence of death and major cardiovascular events.

METHODS

ENIGMA-II is a 7,000-patient, international randomized trial involving patients at risk of coronary artery disease undergoing noncardiac surgery. The patients, health care providers (except for the anesthesiologists), data collectors, and outcome adjudicators are blinded to whether patients receive nitrous oxide-containing or nitrous oxide-free anesthetic. The primary outcome is a composite of death and major nonfatal events (ie, myocardial infarction, cardiac arrest, pulmonary embolism, and stroke) at 30 days after surgery.

RESULTS

At present, ENIGMA-II has randomized >1,000 patients in 22 hospitals in 5 countries. To date, patients' mean age is 70 years, 66% are men, 38% have a history of coronary artery disease, 19% have a history of cerebrovascular disease, and 84% have a history of hypertension. Most patients have undergone intra-abdominal 28%, vascular 32%, and orthopedic 16% surgery.

CONCLUSIONS

The ENIGMA-II Trial will be the largest study yet conducted to ascertain the benefits and risks of removing nitrous oxide from the gas mixture in anesthesia. The results of this large international trial will guide the clinical care of the hundreds of millions of adults undergoing noncardiac surgery annually.

[Perioperative pharmacological myocardial protection. Systematic literature-based process optimization]

Patients with major cardiac risk factors have been suggested to benefit from perioperative beta-blockade. However, the scientific literature on perioperative beta-blockade needs to be interpreted carefully. So far treatment recommendations for millions of patients are based on heterogeneous data from randomized trials with divergent study results. The evidence for a beneficial effect of perioperative beta-blockers is sufficient only for a limited subpopulation of high cardiac risk patients undergoing vascular surgery. Perioperative beta-blocker treatment is not useful in patients with intermediate risk and may even be harmful in patients with low cardiac risk. Therefore, an individualized risk-benefit analysis is an important prerequisite for a rational therapy that may be based on a standardized protocol including the Revised Cardiac Risk Index. Such a protocol is presented in this article. A recently reported trial (POISE) demonstrated that perioperative treatment with high doses of oral metoprolol efficiently reduces the incidence of cardiovascular events. However, due to severe adverse effects (hypotension, bradycardia, stroke) the total mortality was increased. Thus, dose adjustments, safety aspects, and monitoring of beta-blocker therapy seem to be mandatory. So far evidence from relevant trials about how to best implement perioperative beta-blockade is lacking. This article offers a simple clinical concept for this purpose.

Intense cardiac troponin surveillance for long-term benefits is cost-effective in patients undergoing open abdominal aortic surgery: a decision analysis model

BACKGROUND

Strategies to limit adverse cardiac events after vascular surgery continue to evolve. Early recognition and treatment of myocardial ischemia may be a key to improving postoperative survival rates. Cardiac troponin I (cTnI) screening is an effective means of surveillance for postoperative myocardial ischemic injury and has long-term prognostic value.

METHODS

We designed a Markov-based decision analysis model to determine the cost-effectiveness of routine surveillance with cTnI on postoperative Days 0, 1, 2, and 3, with an aim to institute tight heart rate control (60-65 bpm) with close monitoring and coronary care in the intensive care unit for 5 days in patients with cTnI >1.5 ng/mL. The key input variables obtained from published literature were as follows: probability of myocardial infarction, 0.049; cost of cTnI surveillance, $357; cost and efficacy of interventions, $13,145 and 0.55, respectively. The time horizon was lifetime and the target population being individuals aged 65 yr (median) undergoing elective open abdominal aortic surgery. The perspective for analysis was third-party payer.

RESULTS

The incremental cost-effectiveness ratio for cTnI surveillance was $12,641 per quality-adjusted life year compared with standard care without cTnI surveillance. During one-way sensitivity analysis, probability of myocardial infarction and efficacy of interventions were found to influence the cost-effectiveness. Multivariate sensitivity analysis with second-order Monte Carlo simulation revealed that cTnI surveillance was favored in 90.75% of simulations at a commonly used threshold of $50,000 per quality-adjusted life year.

CONCLUSIONS

In patients presenting for elective open abdominal aortic surgery, intensive surveillance with cTnI and early institution of aggressive beta-blockade is cost-effective.

The drive for operating room efficiency will increase quality of patient care

PURPOSE OF REVIEW

The public is demanding that medicine both increase its efficiency and lower its costs. 'Watchdog' groups are scrutinizing our performance, publicizing our results, and forcing us to compete. They want doctors first to use evidence-based medicine to identify truly beneficial healthcare interventions and then to use continuous quality improvement to perform those beneficial interventions consistently at lower costs.

RECENT FINDINGS

A renaissance is underway in our thinking about quality and efficiency in the operating room. 'Work process redesign' and 'the systems approach' are starting to be more than slogans, as researchers redesign the physical environment of the operating room, along with its 'workflow' and methods of communication.

SUMMARY

Soon physicians and hospitals will be receiving 'pay-for-performance', whereby our income will depend on our ability to demonstrate both good patient care processes and good outcomes. Medicine is starting to act like a competitive industry, and this tendency will be good for quality and efficiency in the operating room. Community and academic practitioners need to understand and participate in this transformation in order to be able to influence its evolution and to survive financially.

Recent developments in beta-blockers and anaesthesia

PURPOSE OF REVIEW

To evaluate developments on the subject of beta-blockers and anaesthesia published in the past 12 months. The administration of beta-blockers has been established as a pharmacological approach to reduce cardiac events in the perioperative period. A number of studies and reviews have been published underlining the appropriateness of this approach in patients undergoing non-cardiac as well as cardiac surgery. A lack of transfer of the scientific knowledge to clinical practice is evident not only in the field of perioperative medicine, which results in an under-use of beta-blockers. Open questions are still directed towards the optimal dosage, the effectiveness of chronic beta-blockade and the effects of beta-blockade in traumatized and burned patients.

RECENT FINDINGS

Progress in the use of beta-blockers has been realized by the introduction of institutional protocols. In chronic beta-blockade a simple continuation does not provide effective protection. Improved protection might be gained by the combination of beta-blockers and statins in high-risk patients. The role of beta-blockers in pain management is currently a field of interest, although there seem to be many open questions. There are still doubts about the evidence of perioperative beta-blockade: the results of large trials will be published in the next 2 years. The approach is cost-effective: a comparison with other alternative approaches to cardioprotection is pending.

SUMMARY

There has been significant progress in the use of perioperative beta-blockade. Although a considerable amount of knowledge is obvious, the optimal strategy in different clinical settings is still a matter of debate.

Perioperative myocardial ischemic injury in high-risk vascular surgery patients: Incidence and clinical significance in a prospective clinical trial

OBJECTIVE

The purpose of this study was to assess prospectively the incidence, health care resource utilization, and economic burden associated with perioperative myocardial ischemic injury (PMII) in high-risk patients undergoing noncardiac vascular surgery.

METHODS

Two hundred thirty-six patients consented to participate in a pharmacoeconomic substudy as part of a randomized, multicenter clinical trial. Patients were assessed for myocardial ischemic injury by using clinical, biochemical, and electrocardiographic criteria. PMII was defined as fatal or nonfatal myocardial infarction, new or worsened congestive heart failure, or new arrhythmias. Resource utilization parameters were compared for patients with and without PMII. Patients underwent the following index procedures: open abdominal aortic aneurysm repair (n = 44), bypass for aortoiliac disease (n = 29), bypass for femoropopliteal disease (n = 62), bypass for femorotibial disease (n = 71), extra-anatomic bypass (n = 23), and miscellaneous (n = 7). Patients undergoing carotid endarterectomy or only endovascular interventions were excluded. The incremental cost of PMII was estimated by applying the average costs (adjusted to 2004 US dollars) of the hospital ward (dollar 700.00/d) or intensive care unit (dollar 2500.00/d) to the length of stay differences for patients with and without PMII.

RESULTS

The overall mortality was 3.4% (8/236), and 7 of 8 deaths were related to PMII. PMII occurred in 42 (17.8%) of 236 patients: 22 myocardial infarctions, 11 congestive heart failures, and 12 new arrhythmias (3 patients had 2 PMII events). There was no evidence of differences in the incidence of PMII among the various index procedures. PMII was associated with a dramatic increase in resource utilization. The mean length of stay was 16.8 and 10.0 days for patients with and without PMII, respectively (P < .001). Intensive care unit care was required by 35 (83.3%) of 42 patients with and 121 (62.4%) of 194 patients without PMII (P < .009). The mean intensive care unit length of stay was 6.6 and 3.7 days for patients with and without PMII, respectively (P < .009). Ten (23.8%) of 42 patients with and 20 (10.3%) of 194 patients without PMII returned to the emergency department for care after discharge (P < .02).

CONCLUSIONS

In modern vascular surgery practice, PMII remains common despite the availability of beta-blockers and other preventative strategies. PMII is associated with dramatic increases in resource utilization and cost. The increase in resource utilization associated with PMII resulted in an estimated incremental cost per patient of dollar 9980.00. If 250,000 high-risk open vascular operations are performed annually in the United States, the economic burden of PMII in these procedures alone approximates dollar 444 million. Strategies to decrease PMII incidence and severity should be evaluated in large-scale prospective trials.

Reducing risk of cardiovascular events in noncardiac surgery

Cardiac adverse events are a major cause of complications in noncardiac surgery. The benefit of preventive coronary artery revascularisation in stable patients before noncardiac surgery has recently been clarified: in the short-term there is no reduction in the number of postoperative myocardial infarction, deaths or hospital length of stay. Coronary artery revascularisation should be limited to these patients who have a well-defined need for the procedure, independent of the need of noncardiac surgery. Optimising medical therapy remains the best option for reducing perioperative complications in stable patients: the addition of statin therapy in candidates for noncardiac surgery with known or strongly suspected coronary disease may be conceived. There is compelling evidence for the use of beta-blockers in reducing cardiac risk. This review presents the studies that support the beneficial effect of beta-blockers, pharmacological effects and some practical aspects in noncardiac surgery. In the management of most of these patients, the use of beta-blockers can aid in the avoidance of a preoperative stress test. The remaining problem to solve is the cost-effective identification of the small group of patients in which the protective effect of beta-blocker therapy is insufficient and a cardiac revascularisation should be considered.

[Strategies for perioperative sympatho-modulation]

Despite the growing evidence for the efficacy of different sympatho-modulatory therapies to lower perioperative cardiac morbidity and mortality, such therapeutic strategies are rather infrequently used in daily clinical practice. Most physicians involved in perioperative medicine are aware of the increasing literature related to this topic, but only few comply with current clinical practice guidelines even in the absence of contraindications. This review discusses possible explanations for this reluctance and again summarizes the basic and clinical principles of current sympatho-modulatory therapies including alpha(2)-agonism, beta-adrenergic antagonism, and regional anesthetic techniques in modern anesthetic practice. In addition, the emerging perioperative concept of a patient-tailored individualized pharmacotherapy based on "gene profiling", particularly the adrenergic polymorphisms, is discussed.