Exhibit 99.40 MBNA MASTER CREDIT CARD TRUST II SERIES 1999-E KEY PERFORMANCE FACTORS February 29, 2000 Expected B Maturity 6/17/2002 Blended Coupon 6.0678% Excess Protection Level 3 Month Average 5.40% February, 2000 6.18% January, 2000 5.44% December, 1999 4.57% Cash Yield18.80% Investor Charge Offs 4.75% Base Rate 7.87% Over 30 Day Delinquency 5.01% Seller's Interest 9.54% Total Payment Rate14.30% Total Principal Balance$48,263,301,515.80 Investor Participation Amount$1,000,000,000.00 Seller Participation Amount$4,604,500,997.31