Response to Letter Regarding Article, “A Regional System to Provide Timely Access to Percutaneous Coronary Intervention for ST-Elevation Myocardial Infarction”
We appreciate the kind words of Dr Melandri regarding the development of our regional system to provide timely access for primary percutaneous coronary intervention (PCI) in patients with ST-segment–elevation myocardial infarction (STEMI).1 He raises 2 important points about the number of patients enrolled from the catchment data and the overall risk status of the population. The focus of our article1 was the development of a PCI-based standardized protocol for STEMI patients that included routine transfer from non–PCI-capable hospitals. The program began with a pilot at a single hospital and additional hospitals were then trained at increasing distances from the PCI center. The 1345 consecutive patients included all patients who presented to the PCI hospital and each referral hospital after the level 1 MI protocol was implemented locally. There are 11 PCI-capable hospitals in the Twin Cities metropolitan area, and therefore our series does not represent the entire Twin Cities metropolitan area. The current US healthcare system is fragmented, with multiple different healthcare systems and without an organized transport system. A key point of our article was that a regional PCI program using a standardized protocol can be successful even in the US healthcare system as it exists today.
We believe our consecutive series represents a higher-risk patient population than those in randomized clinical trials or registries such as National Registry of Myocardial Infarction (NRMI) or the Global Registry of Acute Coronary Events (GRACE). With regard to age, 15% of patients were >80 years of age compared with only 9% in NRMI,2 and 25% were >75 years of age compared with 22% in GRACE.3 We included every patient within 24 hours of symptom onset, even those with high-risk clinical characteristics routinely excluded from clinical trials, such as cardiogenic shock (12%) and cardiac arrest before PCI (11%). When compared with the expected death rates based on the Thrombolysis In Myocardial Infarction (TIMI) risk score,4 we had more patients at higher risk as well as lower than expected mortality for every level of TIMI risk. For example, 32% of our patients had a TIMI risk score ≥5 compared with the expected 21%. The 30-day death rate for patients with a TIMI risk score of 8 was 15% compared with the expected 27%. The mortality rate was significantly lower than that reported in the 2001 to 2002 Minnesota Heart Survey, which included participating Minnesota Heart Institute level 1 MI hospitals immediately before implementation of the level 1 MI program in 2003. Finally, 30-day risk-adjusted mortality rates in STEMI patients at the Minneapolis Heart Institute at Abbott Northwestern Hospital were in the lowest 1% of hospitals (n=17) in the United States based on 2005 to 2006 Medicare data.5
Ideally, a national system for STEMI care based on randomized placebo controlled clinical trials could be designed and implemented in the United States,6 but unfortunately this is not feasible at the present time. Our results indicate we have been able to improve treatment times, decrease the number of patients who are eligible but untreated, and increase compliance with guideline-based adjunctive medications at both admission and discharge. All of these factors contribute to lower than expected rate of death in a relatively high-risk cohort of patients. We believe the use of a standardized STEMI PCI protocol with an integrated transfer program can provide the benefits of primary PCI to patients who live up to 210 miles away from a PCI center.
Henry TD, Sharkey SW, Burke MN, Chavez IJ, Graham KJ, Henry CR, Lips DL, Madison JD, Menssen KM, Mooney MR, Newell MC, Pedersen WR, Poulose AK, Traverse JH, Unger BT, Wang YL, Larson DM. A regional system to provide timely access to percutaneous coronary intervention for ST-elevation myocardial infarction. Circulation. 2007; 116: 721–728.
Magid DJ, Wang Y, Herrin J, McNamara RL, Bradley EH, Curtis JP, Pollack CV Jr, French WJ, Blaney ME, Krumholz HM. Relationship between time of day, day of week, timeliness of reperfusion, and in-hospital mortality for patients with acute ST-segment elevation myocardial infarction. JAMA. 2005; 294: 803–812.
Avezum A, Makdisse M, Spencer F, Gore JM, Fox KA, Montalescot G, Eagle KA, White K, Mehta RH, Knobel E, Collet JP; GRACE Investigators. Impact of age on management and outcomes of acute coronary syndrome: Observations from the Global Registry of Acute Coronary Events (GRACE). Am Heart J. 2005; 149: 67–73.
United States Department of Health and Human Services. Hospital compare. Available at: http://www.hospitalcompare.hhs.gov. Accessed December 21, 2007.
Henry TD, Atkins JM, Cunningham MS, Francis GS, Groh WJ, Hong RA, Kern KB, Larson DM, Ohman EM, Ornato JP, Peberdy MA, Rosenberg MJ, Weaver WD. ST elevation myocardial infarction: recommendations on triage of patients to cardiovascular centers of excellence. J Am Coll Cardiol. 2006; 47: 1339–1345.